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The main asteroid belt (shown in white) is located between the orbits of Mars and Jupiter.
.The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter.^ The asteroid belt lies between Mars and Jupiter.
  • The Asteroid Belt 10 February 2010 11:42 UTC www.edinformatics.com [Source type: FILTERED WITH BAYES]
  • Eros or Bust -- NASA spacecraft approaches a near-Earth asteroid 10 February 2010 11:42 UTC science.msfc.nasa.gov [Source type: FILTERED WITH BAYES]

 ^ There are two asteroid belts within our solar system.
  • Dawn Enters Inner Asteroid Belt for the Last Time - It is nearing its mission's objective - Softpedia 10 February 2010 11:42 UTC news.softpedia.com [Source type: General]

 ^ Today, most asteroids orbit the sun in a tightly packed belt located between Mars and Jupiter.
  • Asteroids and Comets, Asteroids and Comets Information, Facts, News, Photos -- National Geographic 10 February 2010 11:42 UTC science.nationalgeographic.com [Source type: General]

 .It is occupied by numerous irregularly shaped bodies called asteroids or minor planets.^ Asteroids are also known as planetoids or minor planets.

 ^ These lumps are called asteroids or minor planets.
  • Wikijunior:Solar System/Asteroid belt - Wikibooks, collection of open-content textbooks 10 February 2010 11:42 UTC en.wikibooks.org [Source type: FILTERED WITH BAYES]

 ^ It is occupied by numerous irregularly shaped bodies called asteroids or minor planets .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.^ The planet's other matter was scattered throughout the entire solar system.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The main belt asteroids are believed to be the remnants of a planet which never formed.
  • Asteroids 10 February 2010 11:42 UTC www.pibburns.com [Source type: FILTERED WITH BAYES]

 ^ Asteroids in our solar system are said to be the detritus of planet formation.
  • CNN.com - Telescope�eyes possible�alien asteroid belt - Apr 20, 2005 10 February 2010 11:42 UTC www.cnn.com [Source type: General]
  • CNN.com - Telescope�eyes possible�alien asteroid belt - Apr 20, 2005 10 February 2010 11:42 UTC edition.cnn.com [Source type: News]
.More than half the mass of the main belt is contained in the four largest objects: Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea.^ The four largest objects, 1 Ceres , 4 Vesta , 2 Pallas and 10 Hygiea , account for half of the belt's total mass, with almost one-third accounted for by Ceres alone.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The main belt 10 has a predetermined stretchability.
  • Muscle strength increasing tool - Patent 7413527 17 September 2009 0:32 UTC www.freepatentsonline.com [Source type: Reference]

 ^ More than half the mass of the main belt is contained in the four largest objects: Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .These have mean diameters of more than 400 km, while Ceres, the main belt's only dwarf planet, is about 950 km in diameter.^ All of these have mean diameters of more than 400 km, while Ceres, the main belt's only dwarf planet , is about 950 km in diameter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Vesta is about 576 km in diameter.
  • Asteroids 10 February 2010 11:42 UTC www.pibburns.com [Source type: FILTERED WITH BAYES]

 ^ Ceres is the largest body in the Main Belt.
  • gazetteer:places:belt:start - FenWiki 10 February 2010 11:42 UTC fnord.sandwich.net [Source type: FILTERED WITH BAYES]

 [1][2][3][4] .The remaining bodies range down to the size of a dust particle.^ The remaining bodies range down to the size of a dust particle.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids range in size from Ceres, about 952 kilometers (592 miles) in diameter, to bodies that are less than 1 kilometer (0.6 mile) across.
  • Solar System Exploration: Planets: Asteroids 10 February 2010 11:42 UTC solarsystem.nasa.gov [Source type: FILTERED WITH BAYES]

 ^ They range in size from almost 1000 km for Ceres (the first asteroid discovered, in 1801) down to less than 10 m for the smallest so far detected.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 .The asteroid material is so thinly distributed that multiple unmanned spacecraft have traversed it without incident.^ The asteroid material is so thinly distributed that multiple unmanned spacecraft have traversed it without incident.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ At the time there was some concern that the debris in the belt would pose a hazard to the spacecraft, but it has since been safely traversed by 9 Earth-based craft without incident.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ As it ventures ever deeper into this vast collection of material between Mars and Jupiter , it may be tempting to think of the spacecraft constantly dodging asteroids.
  • Dawn Journal: In the asteroid belt, but far from asteroids - The Planetary Society Blog | The Planetary Society 10 February 2010 11:42 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 .Nonetheless, collisions between large asteroids do occur, and these can form an asteroid family whose members have similar orbital characteristics and compositions.^ Nonetheless, collisions between large asteroids do occur, and these can form an asteroid family whose members have similar orbital characteristics and compositions.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ EROS EROS. in astronomy, the biggest of the Amor group of near-Earth asteroids , whose orbits tend to fall between those of earth and Mars (see Asteroid ).
  • Search Results 10 February 2010 11:42 UTC www.history.com [Source type: FILTERED WITH BAYES]

 ^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Collisions also produce a fine dust that forms a major component of the zodiacal light.^ Collisions also produce a fine dust that forms a major component of the zodiacal light.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Collisions also produce a fine dust that forms a major component of the zodiacal light .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Individual asteroids within the main belt are categorized by their spectra, with most falling into three basic groups: carbonaceous (C-type), silicate (S-type), and metal-rich (M-type).^ Carbonaceous or C-type Asteroids: More than 75 percent of asteroids fall into this category.
  • Asteroid Facts - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 ^ C-type asteroids are most commonly found in the outer regions of the main asteroid belt.
  • Asteroid Facts - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 ^ APA Style: main-belt asteroid .
  • main-belt asteroid (astronomy) -- Britannica Online Encyclopedia 10 February 2010 11:42 UTC www.britannica.com [Source type: Reference]
.The asteroid belt formed from the primordial solar nebula as a group of planetesimals, the smaller precursors of the planets.^ The main belt asteroids are believed to be the remnants of a planet which never formed.
  • Asteroids 10 February 2010 11:42 UTC www.pibburns.com [Source type: FILTERED WITH BAYES]

 ^ The asteroids are not samples of the primordial Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt formed from the primordial solar nebula as a group of planetesimals, the smaller precursors of the planets.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Between Mars and Jupiter, however, gravitational perturbations from the giant planet imbued the planetesimals with too much orbital energy for them to accrete into a planet.^ It is an area between Mars and Jupiter.
  • National Geographic Explorer (Student Magazine) - Asteroids Rock 10 February 2010 11:42 UTC magma.nationalgeographic.com [Source type: General]

 ^ Between Mars and Jupiter, however, gravitational perturbations from the giant planet imbued the planetesimals with too much orbital energy for them to accrete into a planet.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Early in the history of the solar system, the formation of Jupiter brought an end to the formation of planetary bodies in the gap between Mars and Jupiter and caused the small bodies that occupied this region to collide with one another, fragmenting them into the asteroids we observe today.
  • Solar System Exploration: Planets: Asteroids 10 February 2010 11:42 UTC solarsystem.nasa.gov [Source type: FILTERED WITH BAYES]

 .Collisions became too violent, and instead of sticking together, the planetesimals shattered.^ Collisions became too violent, and instead of sticking together, the planetesimals shattered.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In regions where the average velocity of the collisions was too high, the shattering of planetesimals tended to dominate over accretion, preventing the formation of planet-sized bodies.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ As Jupiter accreted into a giant planet, its gravitational pull began to disturb the orbits of the nearest planetesimals so that collisions became more violent.
  • Main Asteroid Belt 10 February 2010 11:42 UTC solstation.com [Source type: FILTERED WITH BAYES]

 .As a result, most of the main belt's mass has been lost since the formation of the Solar System.^ Wikijunior:Solar System/Asteroid belt .
  • Wikijunior:Solar System/Asteroid belt - Wikibooks, collection of open-content textbooks 10 February 2010 11:42 UTC en.wikibooks.org [Source type: FILTERED WITH BAYES]

 ^ Belts and Moons of our Solar System .
  • Belts and Moons of our Solar System 10 February 2010 11:42 UTC mail.colonial.net [Source type: General]

 ^ As a result, most of the main belt's mass has been lost since the formation of the Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Some fragments can eventually find their way into the inner Solar System, leading to meteorite impacts with the inner planets.^ Inner solar system - views from outside .
  • Asteroid (and Comet) groups 10 February 2010 11:42 UTC sajri.astronomy.cz [Source type: FILTERED WITH BAYES]

 ^ Inner solar system - Tisserand parameter .
  • Asteroid (and Comet) groups 10 February 2010 11:42 UTC sajri.astronomy.cz [Source type: FILTERED WITH BAYES]

 ^ Some fragments can eventually find their way into the inner Solar System, leading to meteorite impacts with the inner planets.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Asteroid orbits continue to be appreciably perturbed whenever their period of revolution about the Sun forms an orbital resonance with Jupiter.^ Hilda asteroids are in a 3:2 resonance of mean motion with Jupiter (that means the orbital period of asteroids and that of Jupiter have ratio of 2:3).
  • Asteroid (and Comet) groups 10 February 2010 11:42 UTC sajri.astronomy.cz [Source type: FILTERED WITH BAYES]

 ^ They were located at positions where their period of revolution about the Sun was an integer fraction of Jupiter's orbital period.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroid orbits continue to be appreciably perturbed whenever their period of revolution about the Sun forms an orbital resonance with Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .At these orbital distances, a Kirkwood gap occurs as they are swept into other orbits.^ At these orbital distances, a Kirkwood gap occurs as they are swept into other orbits.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ To find out how they really originated the composition of these cosmic bodies needs to be taken into consideration.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ These are found at a point one-sixth (or 60°) of an orbit ahead of the planet, and the same distance behind the planet.
  • Wikijunior:Solar System/Asteroid belt - Wikibooks, collection of open-content textbooks 10 February 2010 11:42 UTC en.wikibooks.org [Source type: FILTERED WITH BAYES]

Contents

History of observation

See also: Definition of planet and List of asteroids
Giuseppe Piazzi, discoverer of Ceres, known as a planet for many years, then as asteroid number 1, and eventually, a dwarf planet
.In an anonymous footnote to his 1766 translation of Charles Bonnet's Contemplation de la Nature,[5] the astronomer Johann Daniel Titius von Wittenburg[6][7] noted an apparent pattern in the layout of the planets.^ See also: Definition of planet and List of asteroids Giuseppe Piazzi , discoverer of Ceres , known as a planet for many years, then as asteroid number 1, and eventually, a dwarf planet In an anonymous footnote to his 1766 translation of Charles Bonnet 's Contemplation de la Nature , [ 5 ] the astronomer Johann Daniel Titius von Wittenburg [ 6 ] [ 7 ] noted an apparent pattern in the layout of the planets.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1768, the astronomer Johann Elert Bode made note of Titius's relationship in his Anleitung zur Kenntniss des gestirnten Himmels but did not credit Titius, which led many to refer to it as "Bode's law".
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The relationship was first theorized by Johann Titius in 1766 and was calculated as a mathematical progression by J.E. Bode in 1778.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .If one began a numerical sequence at 0, then included 3, 6, 12, 24, 48, etc., doubling each time, and added four to each number and divided by 10, this produced a remarkably close approximation to the orbits of the known planets as measured in astronomical units.^ The second mission, called Juno, is designed to orbit Jupiter from pole to pole for the first time, conducting an in-depth study of the giant planet's atmosphere and interior.
  • NASA Chooses Three Finalists for Future Space Science Mission to Venus, an Asteroid or the Moon - news from Boston.com 10 February 2010 11:42 UTC finance.boston.com [Source type: News]

 ^ Start with the following series of numbers: 0, 3, 6, 12, 24, 48, 96, 192, 384, 768 With the exception of the first two numbers, the others are twice the value of the preceding number.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Orbit: Average orbital radius: 2.767 astronomical units Orbital inclination: 9.73 degrees Orbital period: 4.60 years Rotational period: 9.076 hours .
  • Asteroid 1 Ceres - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC planetary.org [Source type: FILTERED WITH BAYES]

 .This pattern, now known as the Titius-Bode Law, predicted the semi-major axes of the six planets of the time (Mercury, Venus, Earth, Mars, Jupiter and Saturn) provided one allowed for a "gap" between the orbits of Mars and Jupiter.^ The Titius-Bode Law basically predicts the spacing of the planets or distances from the sun.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ This pattern, now known as the Titius-Bode Law , predicted the semi-major axes of the six planets of the time (Mercury, Venus, Earth, Mars, Jupiter and Saturn) provided one allowed for a "gap" between the orbits of Mars and Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Which planetary orbits match up well with the orbits predicted by the Titius-Bode Law?
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 .In his footnote Titius declared, "But should the Lord Architect have left that space empty?^ In his footnote Titius declared, "But should the Lord Architect have left that space empty?
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Not at all".[6] In 1768, the astronomer Johann Elert Bode made note of Titius's relationship in his Anleitung zur Kenntniss des gestirnten Himmels but did not credit Titius, which led many to refer to it as "Bode's law".[7] When William Herschel discovered Uranus in 1781, the planet's position matched the law almost perfectly, leading astronomers to conclude that there had to be a planet between the orbits of Mars and Jupiter.^ Which planetary orbits match up well with the orbits predicted by the Titius-Bode Law?
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ The Titius-Bode Law does not predict a planet located in Neptune's orbit.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ When William Herschel discovered Uranus in 1781, the planet's position matched the law almost perfectly; leading astronomers to conclude that there had to be a planet between the orbits of Mars and Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]
.In 1800, astronomer Baron Franz Xaver von Zach recruited 24 of his fellows into an informal club he dubbed the "Lilienthal Society". Determined to bring the Solar System to order, the group became known as the "Himmelspolizei", or Celestial Police.^ Determined to bring the Solar System to order, the group became known as the "Himmelspolizei", or Celestial Police.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1800, astronomer Baron Franz Xaver von Zach recruited 24 of his fellows into an informal club he dubbed the "Lilienthal Society".
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This would have required a hugely unlikely combination of gravitational kicks from other planets as the comet travelled into the solar system from the Kuiper Belt or Oort cloud.
  • Technology Review: Blogs: arXiv blog: The Puzzle of the Half-Comet, Half-Asteroid 10 February 2010 11:42 UTC www.technologyreview.com [Source type: General]

 .Notable members included Herschel, British astronomer Royal Nevil Maskelyne, Charles Messier, and Heinrich Olbers.^ Notable members included Herschel, British astronomer Royal Nevil Maskelyne , Charles Messier , and Heinrich Olbers .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [8] .Each astronomer was assigned a 15° region of the zodiac to search for the missing planet.^ Each of the 24 astronomers was assigned a 15° region of the zodiac in which to search for the missing planet.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Hundreds of years ago, astronomical scientists searched for the missing planet in the gap between the inner and outer planets; at the 2.8 Astronomical Unit distance.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [9]
.Only a few months later, a non-member of the Celestial Police confirmed their expectations.^ Only a few months later, a non-member of the Celestial Police confirmed their expectations.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .On January 1, 1801, Giuseppe Piazzi, Chair of Astronomy at the University of Palermo, Sicily, found a tiny moving object in the exact location predicted by the Titius-Bode Law.^ On January 1, 1801, Giuseppe Piazzi , Chair of Astronomy at the University of Palermo , Sicily , found a tiny moving object in the exact location predicted by the Titius-Bode Law.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Titius-Bode Law does not predict a planet located in Neptune's orbit.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ Significant Dates 1801 : Giuseppe Piazzi discovers the first and largest asteroid, Ceres, orbiting between Mars and Jupiter.
  • Solar System Exploration: Planets: Asteroids 10 February 2010 11:42 UTC solarsystem.nasa.gov [Source type: FILTERED WITH BAYES]

 .He dubbed it Ceres, after the Roman goddess of the harvest and patron of Sicily.^ He dubbed it Ceres , after the Roman goddess of the harvest and patron of Sicily.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The first to be discovered was named Ceres after the Roman goddess of growing plants (particularly grain) and of motherly love.
  • Wikijunior:Solar System/Asteroid belt - Wikibooks, collection of open-content textbooks 10 February 2010 11:42 UTC en.wikibooks.org [Source type: FILTERED WITH BAYES]

 .Piazzi initially believed it a comet, but its lack of a coma suggested it was a planet.^ Piazzi initially believed it a comet, but its lack of a coma suggested it was a planet.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [8] .Fifteen months later, Olbers discovered a second object in the same region, Pallas.^ In 1802, Pallas was discovered at the same distance.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Fifteen months later, Olbers discovered a second object in the same region, Pallas .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Hazel McGee discovered this asteroid as part of the on-line Spacewatch Fast Moving Object Program the second UK discovery using this method.
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 .Unlike the other known planets, the objects remained points of light even under the highest telescope magnifications, rather than resolving into discs.^ Unlike the other known planets, the objects remained points of light even under the highest telescope magnifications, rather than resolving into discs.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ It's unlike any other object that we've ever seen.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 ^ And unlike a lot of other asteroids in the Belt, 2 Pallas has most likely remained unchanged since the rocky region between Mars and Jupiter first formed.
  • Meet 2 Pallas, The Newest Protoplanet In The Asteroid Belt - Science - io9 10 February 2010 11:42 UTC io9.com [Source type: General]

 .Apart from their rapid movement, they were indistinguishable from stars.^ Apart from their rapid movement, they were indistinguishable from stars .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 Accordingly, in 1802 William Herschel suggested they be placed into a separate category, named asteroids, after the Greek asteroeides, meaning "star-like".[10][11] Upon completing a series of observations of Ceres and Pallas, he concluded,[12]
.Neither the appellation of planets, nor that of comets, can with any propriety of language be given to these two stars ...^ Neither the appellation of planets, nor that of comets, can with any propriety of language be given to these two stars ...
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ SCIENCE Planet orbits two stars (BBC News) - While some planets have been found orbiting only one of a pair of stars, this planet orbits both.

 ^ These two cosmic chunks of matter are quite small, about the size of some moons of the gas planets.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .They resemble small stars so much as hardly to be distinguished from them.^ They resemble small stars so much as hardly to be distinguished from them.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Astronomers tracked a small non-threatening asteroid heading toward Earth before it became a "shooting star," something they had not done before.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 .From this, their asteroidal appearance, if I take my name, and call them Asteroids; reserving for myself however the liberty of changing that name, if another, more expressive of their nature, should occur.^ From this, their asteroidal appearance, if I take my name, and call them Asteroids; reserving for myself however the liberty of changing that name, if another, more expressive of their nature, should occur.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ To add more dimensions to our mental imagery of Dawn's location, we can take advantage of another celestial reference on December 6, before the triangular alignment of the previous day has changed noticeably.
  • Dawn Journal: In the asteroid belt, but far from asteroids - The Planetary Society Blog | The Planetary Society 10 February 2010 11:42 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 ^ It should be noted that these asteroids are identical in appearance to those in Maelstrom , a clone of Asteroids which was Ambrosia Software's first published game.
  • Asteroid Thicket - Television Tropes & Idioms 10 February 2010 11:42 UTC tvtropes.org [Source type: General]
.Despite Herschel's reservations, for several decades it remained common practice to refer to these objects as planets.^ Despite Herschel's reservations, for several decades it remained common practice to refer to these objects as planets.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1986, millions turned out to watch the return of Halley's comet, but despite the public's fascination, few understand the nature of these objects.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 ^ Unlike the other known planets, the objects remained points of light even under the highest telescope magnifications, rather than resolving into discs.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [5] .By 1807, further investigation revealed two new objects in the region: 3 Juno and 4 Vesta.^ By 1807, further investigation revealed two new objects in the region: 3 Juno and 4 Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Twenty-two miles long, roughly twice the length of Manhattan, Eros may reveal the nature of these mysterious objects.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 [13] .The Napoleonic wars brought this first period of discovery to a close,[13] and it was not until 1845 that another object (5 Astraea) was discovered.^ The Napoleonic wars brought this first period of discovery to a close, [ 13 ] and it was not until 1845 that another object ( 5 Astraea ) was discovered.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However, the discovery of the asteroid 1459 Magnya revealed a slightly different chemical composition from the other basaltic asteroids discovered until then, suggesting a different origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This orbital migration, first postulated by theorist Renu Malhotra in 1993, resulted from countless close encounters with small objects.
  • SkyandTelescope.com - News Blog - Sculpting the Asteroid Belt 10 February 2010 11:42 UTC www.skyandtelescope.com [Source type: General]

 .Shortly thereafter new objects were found at an accelerating rate, and counting them among the planets became increasingly cumbersome.^ Shortly thereafter new objects were found at an accelerating rate, and counting them among the planets became increasingly cumbersome.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ SCIENCE Planet orbits two stars (BBC News) - While some planets have been found orbiting only one of a pair of stars, this planet orbits both.

 ^ SCIENCE Orphan 'planet' findings challenged by new model (Space.com) - Planet-sized objects floating freely among the stars may not be planets at all.

 .Eventually, they were dropped from the planet list as first suggested by Alexander von Humboldt in the early 1850s, and William Herschel's choice of nomenclature, asteroids, gradually came into common use.^ Alexander von Humboldt (1850).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Eventually, they were dropped from the planet list as first suggested by Alexander von Humboldt in the early 1850s, and William Herschel's choice of nomenclature, asteroids, gradually came into common use.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ When the 270-meter (885-foot) asteroid was first discovered in 2004, astronomers estimated the chances of it smashing into Earth in its first flyby in 2029 were as high as 1-in-37.
  • Space head: Russia may send spacecraft to asteroid - NewsFlash - PennLive.com 10 February 2010 11:42 UTC www.lehighvalleylive.com [Source type: News]

 [5]
.The discovery of Neptune in 1846 led to the discrediting of the Titius-Bode Law in the eyes of scientists, as its orbit was nowhere near the predicted position.^ Bode's Law was discarded with the discovery of Neptune in 1846.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Which planetary orbits match up well with the orbits predicted by the Titius-Bode Law?
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ So until that discovery, the Titius-Bode Law was considered very reliable.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 .To date, there is no scientific explanation for the law, and the consensus among astronomers is that it is a coincidence.^ To date, there is no scientific explanation for the law, and the consensus among astronomers is that it is a coincidence.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However further research in to impact events showed that the landslide didn?t have the necessary characteristics to fit such an explanation; mainly, that there was no impact crater.

 ^ There is no indication that Hermes will ever hit Earth, but astronomers will keep an eye on it to get a better handle on the rock's orbit around the Sun and future passes near Earth.
  • Cambridge Conference Correspondence 10 February 2010 11:42 UTC abob.libs.uga.edu [Source type: FILTERED WITH BAYES]

 [14]
.The expression "asteroid belt" comes into use in the very early 1850s, although it is hard to pinpoint who coined the term.^ The expression "asteroid belt" comes into use in the very early 1850s, although it is hard to pinpoint who coined the term.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This hazard comes from the fragments of mutual collisions in the asteroid belt; after their break-up, some of these fragments move towards the earth under the gravitational action of Jupiter.
  • In science fiction movies, the "asteroid belt" is always pictured as a very crowded place. How dense is it really: impossible to navigate, risky or just interesting?: Scientific American 10 February 2010 11:42 UTC www.scientificamerican.com [Source type: FILTERED WITH BAYES]

 ^ Eventually, they were dropped from the planet list as first suggested by Alexander von Humboldt in the early 1850s, and William Herschel's choice of nomenclature, asteroids, gradually came into common use.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The first English use seems to be in the 1850 translation (by E. C. Otté) of Alexander von Humboldt's Cosmos:[15] "[...] and the regular appearance, about the 13th of November and the 11th of August, of shooting stars, which probably form part of a belt of asteroids intersecting the Earth's orbit and moving with planetary velocity". Other early appearances occur in Robert James Mann's A Guide to the Knowledge of the Heavens,[16] "The orbits of the asteroids are placed in a wide belt of space, extending between the extremes of [...]". The American astronomer Benjamin Peirce seems to have adopted that terminology and to have been one of its promoters.^ This asteroid is about 50 feet (15 meters) wide.
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ Other early appearances occur in Robert James Mann's A Guide to the Knowledge of the Heavens , [ 16 ] "The orbits of the asteroids are placed in a wide belt of space, extending between the extremes of [...
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Alexander von Humboldt (1850).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [17] .One hundred asteroids had been located by mid-1868, and in 1891 the introduction of astrophotography by Max Wolf accelerated the rate of discovery still further.^ In 1891, Max Wolf introduced the method of identifying an asteroid by the record of its path on an exposed photographic plate; it appears as a short line in a time exposure, rather than as the sharp point of a star.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 ^ One solution would be to detonate an atomic bomb at some location on the asteroid.
  • ksl.com - Russia may send spacecraft to knock away asteroid 10 February 2010 11:42 UTC www.ksl.com [Source type: Original source]

 ^ Small ones slow down drastically when they hit the atmosphere, and reach a speed of only a few hundred kilometers an hour while they are still many kilometers in the air.
  • Phil Plait's Bad Astronomy: Bad TV 10 February 2010 11:42 UTC www.badastronomy.com [Source type: General]

 [18] .A total of 1,000 asteroids had been found by 1923, 10,000 by 1951, and 100,000 by 1982.[4] Modern asteroid survey systems now use automated means to locate new minor planets in ever-increasing quantities.^ Modern asteroid survey systems now use automated means to locate new minor planets in ever-increasing quantities.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ From now on the asteroid will be known as Minor Planet Offutt (7639).
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 ^ A total of 1,000 asteroids had been found by 1923, 10,000 by 1951, and 100,000 by 1982.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

Origin

The asteroid belt (showing inclinations), with the main belt in red and blue ("core" region in red)

Formation

.In 1802, shortly after discovering Pallas, Heinrich Olbers suggested to William Herschel that Ceres and Pallas were fragments of a much larger planet that once occupied the Mars-Jupiter region, this planet having suffered an internal explosion or a cometary impact many million years before.^ In 1802, Pallas was discovered at the same distance.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ In 1802, shortly after discovering Pallas, Heinrich Olbers suggested to William Herschel that Ceres and Pallas were fragments of a much larger planet that once occupied the Mars-Jupiter region, this planet having suffered an internal explosion or a cometary impact many million years before.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Almost all of it vacated in the first 100 million years of solar-system history due to early run-ins with the planets and with massive super-asteroids that stirred up among the locals before themselves being ejected.
  • SkyandTelescope.com - News Blog - Sculpting the Asteroid Belt 10 February 2010 11:42 UTC www.skyandtelescope.com [Source type: General]

 [19] .Over time however, this hypothesis has fallen from favor.^ Over time however, this hypothesis has fallen from favor.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The large amount of energy that would have been required to destroy a planet, combined with the belt's low combined mass, which is only about 4% of the mass of the Earth's Moon, do not support the hypothesis.^ The large amount of energy that would have been required to destroy a planet, combined with the belt's low combined mass, which is only a small fraction of the mass of the Earth's Moon, do not support the hypothesis.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ That is only about four times the distance from the Earth to the Moon.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 ^ The large amount of energy that would have been required to destroy a planet, combined with the belt's low combined mass, which is only about 4% of the mass of the Earth's Moon , do not support the hypothesis.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Further, the significant chemical differences between the asteroids are difficult to explain if they come from the same planet.^ Further, the significant chemical differences between the asteroids are difficult to explain if they come from the same planet.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids are not all over the solar system; they are primarily in the gap between Mars and Jupiter.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ They are commonly assumed to have originated in the same region as most stony meteorite parent bodies, namely the main asteroid belt located between Mars and Jupiter.
  • PSRD: Iron Meteorites as the Not-So-Distant Cousins of Earth 17 September 2009 0:32 UTC www.psrd.hawaii.edu [Source type: Academic]

 [20] .Today, most scientists accept that, rather than fragmenting from a progenitor planet, the asteroids never formed a planet at all.^ Today, most scientists accept that, rather than fragmenting from a progenitor planet, the asteroids never formed a planet at all.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids, sometimes called minor planets or planetoids, are bodies, primarily of the inner solar system, that are smaller than planets but larger than meteoroids, but exclude comets.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 ^ A sand- to boulder-sized fragment of solid matter that drifts through the solar system rather than traveling in a regular orbit around the sun.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]
.In general in the Solar System, planetary formation is thought to have occurred via a process comparable to the long-standing nebular hypothesis: a cloud of interstellar dust and gas collapsed under the influence of gravity to form a rotating disk of material that then further condensed to form the Sun and planets.^ At the start, the solar nebula was composed of a cloud of gas and dust.
  • PSRD: Tagish Lake Meteorite 10 February 2010 11:42 UTC www.psrd.hawaii.edu [Source type: FILTERED WITH BAYES]

 ^ In general in the Solar System, planetary formation is thought to have occurred via a process comparable to the long-standing nebular hypothesis: a cloud of interstellar dust and gas collapsed under the influence of gravity to form a rotating disk of material that then further condensed to form the Sun and planets.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Stars and planets form from clouds of dust and gas, which were created in supernova explosions.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [21] .During the first few million years of the Solar System's history, an accretion process of sticky collisions caused the clumping of small particles, which gradually increased in size.^ During the first few million years of the Solar System's history, an accretion process of sticky collisions caused the clumping of small particles, which gradually increased in size.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ However, T-Tauri-type Solar winds from a very young Sun, gravitational perturbations from Jupiter developing nearby, and dynamic interactions with other large planetesimals and protoplanets during the first 100 million years, and continuing collisional grinding over the following 4.5 billion years after the formation of the planets, interfered with the formation of a substantial, single planet and caused most of the mass to be lost to the rest of the Solar System and interstellar space.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ A sand- to boulder-sized fragment of solid matter that drifts through the solar system rather than traveling in a regular orbit around the sun.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 .Once the clumps reached sufficient mass, they could draw in other bodies through gravitational attraction and become planetesimals.^ Once the clumps reached sufficient mass, they could draw in other bodies through gravitational attraction and become planetesimals .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Once the clumps reached sufficient mass, they could draw in other bodies through gravitational attraction and become planetesimals.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The other cosmic bodies in orbit around Jupiter are smaller moons, which could be explained as to their origin and composition, as well.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .This gravitational accretion led to the formation of the rocky planets and the gas giants.^ This gravitational accretion led to the formation of the rocky planets and the gas giants.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ This gravitational accretion led to the formation of the rocky planets and the gas giants .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]
.Planetesimals within the region which would become the asteroid belt were too strongly perturbed by Jupiter's gravity to form a planet.^ A planet formed in this location would be round.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ A single planet would have formed.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Planetesimals within the region which would become the asteroid belt were too strongly perturbed by Jupiter's gravity to form a planet.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Instead they continued to orbit the Sun as before, while occasionally colliding.^ Instead they continued to orbit the Sun as before, while occasionally colliding.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ They revolve around the sun in highly elliptical orbits.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ It comes closer to Earth than any other object in a 'retrograde' orbit, and astronomers think they should have spotted it before.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 [22] .In regions where the average velocity of the collisions was too high, the shattering of planetesimals tended to dominate over accretion,[23] preventing the formation of planet-sized bodies.^ In regions where the average velocity of the collisions was too high, the shattering of planetesimals tended to dominate over accretion, [ 23 ] preventing the formation of planet-sized bodies.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ There is an apparent concentration of M-class (metallic) asteroids in the middle of the belt, at 2.5–3.0 AU. Asteroids are thought to have formed through the accretion of metre-sized bodies, but were prevented from aggregating into a planet by the gravitational effect of Jupiter, which had already formed.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 ^ It is argued that a collision with another cosmic body like a hit by a comet or meteor even several kilometers in size could not destroy a planet.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Orbital resonances occurred where the orbital period of an object in the belt formed an integer fraction of the orbital period of Jupiter, perturbing the object into a different orbit; the region lying between the orbits of Mars and Jupiter contains many such orbital resonances.^ The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Main asteroid belt between Mars and Jupiter .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ The main asteroid belt (shown in white) is located between the orbits of Mars and Jupiter .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .As Jupiter migrated inward following its formation, these resonances would have swept across the asteroid belt, dynamically exciting the region's population and increasing their velocities relative to each other.^ These asteroids can categorized by any of the following .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ As Jupiter migrated inward following its formation, these resonances would have swept across the asteroid belt, dynamically exciting the region's population and increasing their velocities relative to each other.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [24]
.During the early history of the Solar System, the asteroids melted to some degree, allowing elements within them to be partially or completely differentiated by mass.^ During the early history of the Solar System, the asteroids melted to some degree, allowing elements within them to be partially or completely differentiated by mass.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroids are not samples of the primordial Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids are also categorized by their locations in the solar system.
  • Asteroid Facts - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 .Some of the progenitor bodies may even have undergone periods of explosive volcanism and formed magma oceans.^ Some of the progenitor bodies may even have undergone periods of explosive volcanism and formed magma oceans.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ According to some models, there was insufficient outgassing of water during the Earth's formative period to form the oceans, necessitating an external source such as a cometary bombardment.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Scientists also speculate that some NEAs may be the nuclei of dead, short-period comets that have burned off all their gases.
  • Asteroid Facts - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 .However, because of the relatively small size of the bodies, the period of melting was necessarily brief (compared to the much larger planets), and had generally ended about 4.5 billion years ago, in the first tens of millions years of formation.^ However, because of the relatively small size of the bodies, the period of melting was necessarily brief (compared to the much larger planets), and had generally ended about 4.5 billion years ago, in the first tens of millions years of formation.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Because of its small size, it does not have sufficient gravitational influence to have cleared its neighborhood of other, smaller bodies in similar orbits, so under the International Astronomical Union's new definition scheme Ceres is considered to be a "dwarf planet," and may very likely be the only dwarf planet in the asteroid belt.
  • Asteroid 1 Ceres - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC planetary.org [Source type: FILTERED WITH BAYES]

 ^ However, T-Tauri-type Solar winds from a very young Sun, gravitational perturbations from Jupiter developing nearby, and dynamic interactions with other large planetesimals and protoplanets during the first 100 million years, and continuing collisional grinding over the following 4.5 billion years after the formation of the planets, interfered with the formation of a substantial, single planet and caused most of the mass to be lost to the rest of the Solar System and interstellar space.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [25] .In August 2007, a study of zircon crystals in an Antarctic meteorite believed to have originated from 4 Vesta suggested that it, and by extension the rest of the asteroid belt, had formed rather quickly, within ten million years of the Solar System origin.^ The asteroids are not samples of the primordial Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Solar System is big , and the asteroid belt has a very low density.
  • Phil Plait's Bad Astronomy: Bad TV 10 February 2010 11:42 UTC www.badastronomy.com [Source type: General]

 ^ The asteroid belt formed at the time dinosaurs originated.

 [26]

Evolution

.The asteroids are not samples of the primordial Solar System.^ The asteroids are not samples of the primordial Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids are also categorized by their locations in the solar system.
  • Asteroid Facts - Explore the Cosmos | The Planetary Society 17 September 2009 0:32 UTC www.planetary.org [Source type: FILTERED WITH BAYES]

 ^ Asteroids, sometimes called minor planets or planetoids, are bodies, primarily of the inner solar system, that are smaller than planets but larger than meteoroids, but exclude comets.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 .They have undergone considerable evolution since their formation, including internal heating (in the first few tens of millions of years), surface melting from impacts, space weathering from radiation, and bombardment by micrometeorites.^ They have undergone considerable evolution since their formation, including internal heating (in the first few tens of millions of years), surface melting from impacts, space weathering from radiation, and bombardment by micrometeorites .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1999 the probe Deep Space 1 accomplished the then closest-ever flyby of an asteroid, coming within 16 mi (26 km) of the surface of Braille ; spectroscopic data suggests that Braille broke off from Vesta millions of years ago.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 ^ The energy released is often enough to heat and vaporize both the impacting object and the surface where it hits.

 [27] .While some scientists refer to the asteroids as residual planetesimals,[28] other scientists consider them distinct.^ While some scientists refer to the asteroids as residual planetesimals, [ 28 ] other scientists consider them distinct.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Although scientists can calculate a most-likely orbit from these early observations, each single observation of the asteroid's position contains some uncertainty.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ In addition, some planetesimals left over from the formation of Jupiter may have been scattered into the asteroid belt.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 [29]
.The current asteroid belt is believed to contain only a small fraction of the mass of the primordial belt.^ The current asteroid belt is believed to contain only a small fraction of the mass of the primordial belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ "Mass distribution in the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Over time, a small number of those pieces, many of them close to a mile in diameter, fell out of the asteroid belt’s orbit.
  • Asteroid Belt Collision Likely Led to Dinosaurs’ Death | Wired Science | Wired.com 10 February 2010 11:42 UTC www.wired.com [Source type: General]

 .Computer simulations suggest that the original asteroid belt may have contained mass equivalent to the Earth.^ Computer simulations suggest that the original asteroid belt may have contained mass equivalent to the Earth.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ "Mass distribution in the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In August 2007, a study of zircon crystals in an Antarctic meteorite believed to have originated from 4 Vesta suggested that it, and by extension the rest of the asteroid belt, had formed rather quickly, within ten million years of the Solar System origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Primarily because of gravitational perturbations, most of the material was ejected from the belt within about a million years of formation, leaving behind less than 0.1% of the original mass.^ Primarily because of gravitational perturbations, most of the material was ejected from the belt within about a million years of formation, leaving behind less than 0.1% of the original mass.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However, T-Tauri-type Solar winds from a very young Sun, gravitational perturbations from Jupiter developing nearby, and dynamic interactions with other large planetesimals and protoplanets during the first 100 million years, and continuing collisional grinding over the following 4.5 billion years after the formation of the planets, interfered with the formation of a substantial, single planet and caused most of the mass to be lost to the rest of the Solar System and interstellar space.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ In August 2007, a study of zircon crystals in an Antarctic meteorite believed to have originated from 4 Vesta suggested that it, and by extension the rest of the asteroid belt, had formed rather quickly, within ten million years of the Solar System origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [22] .Since their formation, the size distribution of the asteroid belt has remained relatively stable: there has been no significant increase or decrease in the typical dimensions of the main belt asteroids.^ There may be over one million asteroids in the main Asteroid Belt.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ Since their formation, the size distribution of the asteroid belt has remained relatively stable: there has been no significant increase or decrease in the typical dimensions of the main belt asteroids.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ "Mass distribution in the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [30]
.The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU, can be considered the inner boundary of the main belt.^ The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU , can be considered the inner boundary of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Near-Earth asteroids seem to have broken away from the main Asteroid Belt which orbits the Sun at a distance between Mars and Jupiter.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 ^ The solar system contains several million asteroids, most of which reside in the Main Asteroid Belt between Mars and Jupiter.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 .Perturbations by Jupiter send bodies straying there into unstable orbits.^ There is an apparent concentration of M-class (metallic) asteroids in the middle of the belt, at 2.5–3.0 AU. Asteroids are thought to have formed through the accretion of metre-sized bodies, but were prevented from aggregating into a planet by the gravitational effect of Jupiter, which had already formed.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 ^ The other cosmic bodies in orbit around Jupiter are smaller moons, which could be explained as to their origin and composition, as well.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Called Kirkwood gaps, they are thought to be cleared of debris by Jupiter's gravity, which causes any objects orbiting there to move chaotically.
  • Asteroid belt may bear scars of planets' migration - space - 25 February 2009 - New Scientist 10 February 2010 11:42 UTC www.newscientist.com [Source type: News]

 .Most bodies formed inside the radius of this gap were swept up by Mars (which has an aphelion at 1.67 AU) or ejected by its gravitational perturbations in the early history of the Solar System.^ Most bodies formed inside the radius of this gap were swept up by Mars (which has an aphelion at 1.67 AU) or ejected by its gravitational perturbations in the early history of the Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Small Solar System bodies .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Almost all of it vacated in the first 100 million years of solar-system history due to early run-ins with the planets and with massive super-asteroids that stirred up among the locals before themselves being ejected.
  • SkyandTelescope.com - News Blog - Sculpting the Asteroid Belt 10 February 2010 11:42 UTC www.skyandtelescope.com [Source type: General]

 [31] .The Hungaria asteroids lie closer to the Sun than the 4:1 resonance, but are protected from disruption by their high inclination.^ The Hungaria asteroids lie closer to the Sun than the 4:1 resonance, but are protected from disruption by their high inclination.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Weaker resonances occur at other semi-major axis values, with fewer asteroids found than nearby.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The plane of Toutatis' orbit is closer to the plane of the Earth's orbit than any known Earth-orbit-crossing asteroid.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 [32]
.When the main belt was first formed, the temperatures at a distance of 2.7 AU from the Sun formed a "snow line" below the condensation point of water.^ The temperature of the asteroid belt varies with the distance from the Sun.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ When the main belt was first being formed, the temperatures at a distance of 2.7 AU from the Sun formed a "snow line" below the condensation point of water.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; its composition is mainly of basaltic rock such as olivine.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Planetesimals formed beyond this radius were able to accumulate ice.^ Planetesimals formed beyond this radius were able to accumulate ice.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [33][34] .In 2006 it was announced that a population of comets had been discovered within the asteroid belt beyond the snow line, which may have provided a source of water for Earth's oceans.^ Could an asteroid or comet hit earth.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 ^ In 2006 it was announced that a population of comets had been discovered within the asteroid belt beyond the snow line, which may have provided a source of water for Earth's oceans.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Could a comet or asteroid hit earth?
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 .According to some models, there was insufficient outgassing of water during the Earth's formative period to form the oceans, requiring an external source such as a cometary bombardment.^ According to some models, there was insufficient outgassing of water during the Earth's formative period to form the oceans, necessitating an external source such as a cometary bombardment.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; its composition is mainly of basaltic rock such as olivine.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ At the time there was some concern that the debris in the belt would pose a hazard to the spacecraft, but it has since been safely traversed by 9 Earth-based craft without incident.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [35]

Characteristics

The asteroid 951 Gaspra, the first ever imaged by a spacecraft, taken by Galileo as it passed by it in 1991; the colors are exaggerated
Allende is a carbonaceous chondrite meteorite that fell to Earth in Mexico in 1969.
.Contrary to popular imagery, the asteroid belt is mostly empty.^ Contrary to popular imagery, the asteroid belt is mostly empty.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ STORY OF NEAR AND EROS » Spacecraft from Earth that have flown through the Asteroid Belt have found it mostly empty because, after all, the individual asteroids are separated by great distances.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 ^ Eve Online has densely packed asteroid belts which form partial arcs around an empty point.
  • Asteroid Thicket - Television Tropes & Idioms 10 February 2010 11:42 UTC tvtropes.org [Source type: General]

 .The asteroids are spread over such a large volume that it would be improbable to reach an asteroid without aiming carefully.^ The asteroids are spread over such a large volume that it would be highly improbable to reach an asteroid without aiming carefully.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ At the current rate of impacts, we would expect about one large asteroid to impact Earth every 100 million years or so.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Asteroids do exist, and an impact by a large one would be a bad thing.
  • Phil Plait's Bad Astronomy: Bad TV 10 February 2010 11:42 UTC www.badastronomy.com [Source type: General]

 .Nonetheless, hundreds of thousands of asteroids are currently known, and the total number ranges in the millions or more, depending on the lower size cutoff.^ Nonetheless, hundreds of thousands of asteroids are currently known, and the total number ranges in the millions or more, depending on the lower size cutoff.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Hundreds, if not thousands, of asteroids are seen.
  • Phil Plait's Bad Astronomy: Bad TV 10 February 2010 11:42 UTC www.badastronomy.com [Source type: General]

 ^ At the current rate of impacts, we would expect about one large asteroid to impact Earth every 100 million years or so.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Over 200 asteroids are known to be larger than 100 km,[36] while a survey in the infrared wavelengths shows that the main belt has 700,000 to 1.7 million asteroids with a diameter of 1 km or more.^ There may be over one million asteroids in the main Asteroid Belt.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ Main belt asteroid, 195 km in diameter, with an orbital period of 5.7 years .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ More than 7,000 asteroids have been discovered.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 [37] The apparent magnitudes of most of the known asteroids are 11–19, with the median at about 16.[38]
.The total mass of the asteroid belt is estimated to be 3.0×1021 to 3.6×1021 kilograms, which is just 4% of the Moon.^ The total mass of the asteroid belt is estimated to be 3.0×10 21 to 3.6×10 21 kilograms, which is just 4% of the Moon .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The total mass of all asteroids is 4 × 10 21 kg, about one-twentieth the mass of the Moon.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 ^ "Mass distribution in the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [1][2] .The four largest objects, Ceres, 4 Vesta, 2 Pallas and 10 Hygiea, account for half of the belt's total mass, with almost one-third accounted for by Ceres alone.^ The four largest objects, 1 Ceres , 4 Vesta , 2 Pallas and 10 Hygiea , account for half of the belt's total mass, with almost one-third accounted for by Ceres alone.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ More than half the mass of the main belt is contained in the four largest objects: Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ More than half the mass of the main belt is contained in the four largest objects: Ceres , 4 Vesta , 2 Pallas , and 10 Hygiea .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [3][4] Ceres's orbital distance, 2.766 AU, is also very close to the location of the belt's center of mass, 2.8 AU.[39]

Composition

.The current belt consists primarily of three categories of asteroids: C-type or carbonaceous asteroids, S-type or silicate asteroids, and M-type or metallic asteroids.^ The current belt consists primarily of three categories of asteroids: C-type or carbonaceous asteroids, S-type or silicate asteroids, and M-type or metallic asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Individual asteroids within the main belt are categorized by their spectra , with most falling into three basic groups: carbonaceous ( C-type ), silicate ( S-type ), and metal-rich ( M-type ).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids consist of 3 types of matter: nickel/iron as it exists in the center of planets, igneous rock as it exists in the depth of a planet and earth type rocks as they exist in the crust of a planet.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
.Carbonaceous asteroids, as their name suggests, are carbon-rich and dominate the belt's outer regions.^ Carbonaceous asteroids, as their name suggests, are carbon-rich and dominate the belt's outer regions.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [40] .Together they comprise over 75% of the visible asteroids.^ Together they comprise over 75% of the visible asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .They are more red in hue than the other asteroids and have a very low albedo.^ They are more red in hue than the other asteroids and have a very low albedo .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Other than that, they are completely unrelated.
  • ksl.com - Russia may send spacecraft to knock away asteroid 10 February 2010 11:42 UTC www.ksl.com [Source type: Original source]

 ^ More than 7,000 asteroids have been discovered.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]

 .Their surface composition is similar to carbonaceous chondrite meteorites.^ Their surface composition is similar to carbonaceous chondrite meteorites .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The majority (C-type) are similar to carbon-chrondite meteorites with approximately the same composition as the sun (excluding hydrogen) and are relatively dark.
  • asteroid Facts, information, pictures | Encyclopedia.com articles about asteroid 10 February 2010 11:42 UTC www.encyclopedia.com [Source type: FILTERED WITH BAYES]

 ^ Lazzarin, M., M. DiMartino, M.A. Barucci, A. Doressoundiram, and M. Florczak: Compositional properties of near-Earth asteroids: Spectroscopic comparison with ordinary chondrite meteorites.
  • Bibliography 10 February 2010 11:42 UTC nai.arc.nasa.gov [Source type: Academic]

 .Chemically, their spectra match the primordial composition of the early Solar System, with only the lighter elements and volatiles removed.^ The asteroids are not samples of the primordial Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Chemically, their spectra match the primordial composition of the early Solar System, with only the lighter elements and volatiles removed.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; its composition is mainly of basaltic rock such as olivine.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
.S-type or silicate-rich asteroids are more common toward the inner region of the belt, within 2.5 AU of the Sun.^ S-type or silicate -rich asteroids are more common toward the inner region of the belt, within 2.5 AU of the Sun.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ They thus bear little resemblance to Sol's massive asteroid belt, and are more like clusters of asteroids.
  • Asteroid Thicket - Television Tropes & Idioms 10 February 2010 11:42 UTC tvtropes.org [Source type: General]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [40][41] .The spectra of their surfaces reveal the presence of silicates and some metal, but no significant carbonaceous compounds.^ The spectra of their surfaces reveal the presence of silicates and some metal, but no significant carbonaceous compounds.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Individual asteroids within the main belt are categorized by their spectra , with most falling into three basic groups: carbonaceous ( C-type ), silicate ( S-type ), and metal-rich ( M-type ).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The current belt consists primarily of three categories of asteroids: C-type or carbonaceous asteroids, S-type or silicate asteroids, and M-type or metallic asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .This indicates that their materials have been significantly modified from their primordial composition, probably through melting and reformation.^ This indicates that their materials have been significantly modified from their primordial composition, probably via melting and reformation.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .They have a relatively high albedo, and form about 17% of the total asteroid population.^ They have a relatively high albedo, and form about 17% of the total asteroid population.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In the more distant past, the Datura cluster appears to have formed about 450 million years ago from a collision with a main belt asteroid.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ See the article about the Flora Asteroid Clan which includes an animation of how asteroid families may have formed.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]
.M-type (metal-rich) asteroids form about 10% of the total population; their spectra resemble that of iron-nickel.^ ALEX BEVAN: In Australia, we have a group of thirteen craters that was formed by an impact of a large iron meteorite around about five thousand years ago.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 ^ The impactor, a stony and (or) iron asteroid , is estimated to have been about 350 m in diameter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Asteroids consist of 3 types of matter: nickel/iron as it exists in the center of planets, igneous rock as it exists in the depth of a planet and earth type rocks as they exist in the crust of a planet.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Some are believed to have formed from the metallic cores of differentiated progenitor bodies that were disrupted through collision.^ Some are believed to have formed from the metallic cores of differentiated progenitor bodies that were disrupted through collision.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Some of the progenitor bodies may even have undergone periods of explosive volcanism and formed magma oceans.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ "Our work," says Jura, "shows that at least some kinds of large-ish asteroid bodies have been formed elsewhere."

 .However, there are also some silicate compounds that can produce a similar appearance.^ However, there are also some silicate compounds that can produce a similar appearance.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The spectra of their surfaces reveal the presence of silicates and some metal, but no significant carbonaceous compounds.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .For example, the large M-type asteroid 22 Kalliope does not appear to be primarily composed of metal.^ For example, the large M-type asteroid 22 Kalliope does not appear to be primarily composed of metal.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Minor Planet Relatively small celestial bodies composed of metals and rocks that revolve around the sun, a.k.a asteroid and planetoid .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ Individual asteroids within the main belt are categorized by their spectra , with most falling into three basic groups: carbonaceous ( C-type ), silicate ( S-type ), and metal-rich ( M-type ).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [42] .Within the main belt, the number distribution of M-type asteroids peaks at a semi-major axis of about 2.7 AU.[43] It is not yet clear whether all M-types are compositionally similar, or whether it is a label for several varieties which do not fit neatly into the main C and S classes.^ Apollo asteroid with a period of 1.71 years and a semi-major axis of 1.42 AU .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ Within the main belt, the number distribution of M-type asteroids peaks at a semi-major axis of about 2.7 AU. [ 43 ] It is not yet clear whether all M-types are compositionally similar, or whether it is a label for several varieties which do not fit neatly into the main C and S classes.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ "Mass distribution in the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [44]
.One mystery of the asteroid belt is the relative rarity of V-type, or basaltic asteroids.^ One mystery of the asteroid belt is the relative rarity of V-type , or basaltic asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ There may be over one million asteroids in the main Asteroid Belt.
  • NOVA Online | Teachers | Viewing Ideas | NOVA scienceNOW: Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

 ^ "Two new basaltic asteroids in the Outer Main Belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [45] .Theories of asteroid formation predict that objects the size of Vesta or larger should form crusts and mantles, which would be composed mainly of basaltic rock, resulting in more than half of all asteroids being composed either of basalt or olivine.^ Theories of asteroid formation predict that objects the size of Vesta or larger should form crusts and mantles, which would be composed mainly of basaltic rock, resulting in more than half of all asteroids being composed either of basalt or olivine .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids, sometimes called minor planets or planetoids, are bodies, primarily of the inner solar system, that are smaller than planets but larger than meteoroids, but exclude comets.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 ^ Long term studies of a given asteroid can result in determining the phase coefficients, i.e., the absolute magnitude and slope parameters that define the asteroids brightness especially near opposition when the "opposition effect" causes the asteroid to brighten faster than at larger phase angles.
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 .Observations, however, suggest that 99 percent of the predicted basaltic material is missing.^ Observations, however, suggest that 99 percent of the predicted basaltic material is missing.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However, the discovery of the asteroid 1459 Magnya revealed a slightly different chemical composition from the other basaltic asteroids discovered until then, suggesting a different origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [46] .Until 2001, most basaltic bodies discovered in the asteroid belt were believed to originate from the asteroid Vesta (hence their name V-type).^ One mystery of the asteroid belt is the relative rarity of V-type , or basaltic asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Until 2001, most basaltic bodies discovered in the asteroid belt were believed to originate from the asteroid Vesta (hence their name V-type).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This hypothesis was reinforced by the further discovery in 2007 of two asteroids in the outer belt, 7472 Kumakiri and (10537) 1991 RY16 , with differing basaltic composition that could not have originated from Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .However, the discovery of the asteroid 1459 Magnya revealed a slightly different chemical composition from the other basaltic asteroids discovered until then, suggesting a different origin.^ However, the discovery of the asteroid 1459 Magnya revealed a slightly different chemical composition from the other basaltic asteroids discovered until then, suggesting a different origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This hypothesis was reinforced by the further discovery in 2007 of two asteroids in the outer belt, 7472 Kumakiri and (10537) 1991 RY16 , with differing basaltic composition that could not have originated from Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Napoleonic wars brought this first period of discovery to a close, [ 13 ] and it was not until 1845 that another object ( 5 Astraea ) was discovered.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [46] .This hypothesis was reinforced by the further discovery in 2007 of two asteroids in the outer belt, 7472 Kumakiri and (10537) 1991 RY16, with differing basaltic composition that could not have originated from Vesta.^ "Two new basaltic asteroids in the Outer Main Belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This hypothesis was reinforced by the further discovery in 2007 of two asteroids in the outer belt, 7472 Kumakiri and (10537) 1991 RY16 , with differing basaltic composition that could not have originated from Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; its composition is mainly of basaltic rock such as olivine.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .These latter two are the only V-type asteroids discovered in the outer belt to date.^ "Two new basaltic asteroids in the Outer Main Belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ These latter two are the only V-type asteroids discovered in the outer belt to date.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ This hypothesis was reinforced by the further discovery in 2007 of two asteroids in the outer belt, 7472 Kumakiri and (10537) 1991 RY16 , with differing basaltic composition that could not have originated from Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [45]
.The temperature of the asteroid belt varies with the distance from the Sun.^ The temperature of the asteroid belt varies with the distance from the Sun.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However, comets take months to get from the distance of the asteroid belt to Earth's orbit.
  • Phil Plait's Bad Astronomy: Bad TV 10 February 2010 11:42 UTC www.badastronomy.com [Source type: General]

 ^ For going from the earth to the asteroid belt, would there also be calcualtion for the escape velocity from the sun, starting at the distance of the earth's orbit?
  • So, how much energy *does* it take to fire a pound of bacon into the Asteroid Belt? - Straight Dope Message Board 10 February 2010 11:42 UTC boards.straightdope.com [Source type: FILTERED WITH BAYES]

 .For dust particles within the belt, typical temperatures range from 200 K (−73 °C) at 2.2 AU down to 165 K (−108 °C) at 3.2 AU[47] However, due to rotation, the surface temperature of an asteroid can vary considerably as the sides are alternately exposed to solar radiation and then to the stellar background.^ The remaining bodies range down to the size of a dust particle.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The temperature of the asteroid belt varies with the distance from the Sun.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ III - Dust near the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

Main-belt comets

Main article: Main-belt comet
.Several otherwise unremarkable bodies in the outer belt show cometary activity.^ Main article: Main-belt comet Several otherwise unremarkable bodies in the outer belt show cometary activity.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The wire-like piece 15 B may be embedded in the outer portion of the main belt 10 or otherwise may be provided on the inside of the main belt 10 and the outside of the tube 13 .
  • Muscle strength increasing tool - Patent 7413527 17 September 2009 0:32 UTC www.freepatentsonline.com [Source type: Reference]

 ^ Main article: Asteroid family This plot of orbital inclination ( i p ) versus eccentricity ( e p ) for the numbered main belt asteroids clearly shows several clumps of asteroid families.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Since their orbits cannot be explained through capture of classical comets, it is thought that many of the outer asteroids may be icy, with the ice occasionally exposed to sublimation through small impacts.^ Harris, A.W.: Can we defend the Earth against impacts by comets and small asteroids?
  • Bibliography 10 February 2010 11:42 UTC nai.arc.nasa.gov [Source type: Academic]

 ^ The Reptilians love to use comets and asteroids as weapons and ships, using them to travel through the stars.

 ^ The series, targeted to pre-kindergarteners through third-graders, delivers both astronomy-based science education (orbits, eclipses, moon phases, asteroids, comets, gravity), as well as character- building lessons.
  • Zula Patrol | KQED Public Media for Northern CA 10 February 2010 11:42 UTC www.kqed.org [Source type: General]

 .Main Belt comets may have been a major source of the Earth's oceans, since the deuterium-hydrogen ratio is too low for classical comets to have been the principal source.^ Main Belt comets may have been a major source of the Earth's oceans, since the deuterium-hydrogen ratio is too low for classical comets to have been the principal source.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Main-belt comets .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Since their orbits cannot be explained through capture of classical comets, it is thought that many of the outer asteroids may be icy, with the ice occasionally exposed to sublimation through small impacts.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [48]

Orbits and rotations

The asteroid belt (showing eccentricities), with the main belt in red and blue ("core" region in red)
.Most asteroids within the main belt have orbital eccentricities of less than 0.4, and an inclination of less than 30°.^ Main belt asteroid with an orbital period of 3.19 years .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ The asteroid belt (showing eccentricities), with the main belt in red and blue ("core" region in red) Most asteroids within the main belt have orbital eccentricities of less than 0.4, and an inclination of less than 30°.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .The orbital distribution of the asteroids reaches a maximum at an eccentricity of around 0.07 and an inclination below 4°.^ The orbital distribution of the asteroids reaches a maximum at an eccentricity of around 0.07 and an inclination below 4°.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroids in the main belt have mean orbital period near 4.4 years so some or many could complete > = 1E+9 revolutions around the Sun.
  • SkyandTelescope.com - News Blog - Sculpting the Asteroid Belt 10 February 2010 11:42 UTC www.skyandtelescope.com [Source type: General]

 ^ These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [38] .Thus while a typical asteroid has a relatively circular orbit and lies near the plane of the ecliptic, some asteroid orbits can be highly eccentric or travel well outside the ecliptic plane.^ Thus while a typical asteroid has a relatively circular orbit and lies near the plane of the ecliptic , some asteroid orbits can be highly eccentric or travel well outside the ecliptic plane.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1918, the Japanese astronomer Kiyotsugu Hirayama noticed that the orbits of some of the asteroids had similar parameters, forming families or groups.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Near-Earth asteroids seem to have broken away from the main Asteroid Belt which orbits the Sun at a distance between Mars and Jupiter.
  • Space Today Online - Solar System - Asteroids 10 February 2010 11:42 UTC www.spacetoday.org [Source type: FILTERED WITH BAYES]
.Sometimes, the term main belt is used to refer only to the more compact "core" region where the greatest concentration of bodies is found.^ Sometimes, the term main belt is used to refer only to the more compact "core" region where the greatest concentration of bodies is found.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The expression "asteroid belt" comes into use in the very early 1850s, although it is hard to pinpoint who coined the term.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .This lies between the strong 4:1 and 2:1 Kirkwood gaps at 2.06 and 3.27 AU, and at orbital eccentricities less than roughly 0.33, along with orbital inclinations below about 20°.^ This lies between the strong 4:1 and 2:1 Kirkwood gaps at 2.06 and 3.27 AU , and at orbital eccentricities less than roughly 0.33, along with orbital inclinations below about 20°.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU , can be considered the inner boundary of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .This "core" region contains approximately 93.4% of all numbered minor planets within the Solar System.^ This "core" region contains approximately 93.4% of all numbered minor planets within the Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroids, sometimes called minor planets or planetoids, are bodies, primarily of the inner solar system, that are smaller than planets but larger than meteoroids, but exclude comets.
  • Asteroid // Current 10 February 2010 11:42 UTC current.com [Source type: FILTERED WITH BAYES]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [49]
.Measurements of the rotation rates of large asteroids in the main belt show that there is an upper limit.^ Measurements of the rotation rates of large asteroids in the main belt show that there is an upper limit.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ There are problems with that if the asteroid is rotating, of course.
  • ksl.com - Russia may send spacecraft to knock away asteroid 10 February 2010 11:42 UTC www.ksl.com [Source type: Original source]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .No asteroid with a diameter larger than 100 meters has a period of rotation faster than 2.2 hours.^ Long term studies of a given asteroid can result in determining the phase coefficients, i.e., the absolute magnitude and slope parameters that define the asteroids brightness especially near opposition when the "opposition effect" causes the asteroid to brighten faster than at larger phase angles.
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ There are several asteroids smaller than 100m with periods < 2.25h, some as short as a few minutes.
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ Uncertainty of the asteroid's position is within 10s of kilometers, more than enough to make sure theres no risk of that.
  • Slashdot Science Story | Simulation of Close Asteroid Fly-By 10 February 2010 11:42 UTC science.slashdot.org [Source type: General]

 .For asteroids rotating faster than approximately this rate, the centrifugal force at the surface is greater than the gravitational force, so any loose surface material would be flung out.^ For asteroids rotating faster than approximately this rate, the centrifugal force at the surface is greater than the gravitational force, so any loose surface material would be flung out.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Ceres has a much higher absolute magnitude than the other asteroids, of around 3.32, [ 63 ] and may possess a surface layer of ice.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Once a typical pair of motion rates have been established it is possible to stack images so that most asteroids in the FOV are approximately aligned.
  • Asteroid Hubting 10 February 2010 11:42 UTC brucegary.net [Source type: FILTERED WITH BAYES]

 .However, a solid object should be able to rotate much more rapidly.^ However, a solid object should be able to rotate much more rapidly.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ From this, their asteroidal appearance, if I take my name, and call them Asteroids; reserving for myself however the liberty of changing that name, if another, more expressive of their nature, should occur.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However, for these smaller objects, the maybe hundred-meter fragments of asteroids which mostly blow up in the atmosphere but nevertheless cause widespread devastation underneath, those occur much more frequently.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 .This suggests that most asteroids with a diameter over 100 metres are rubble piles formed through accumulation of debris after collisions between asteroids.^ This suggests that the majority of asteroids with a diameter over 100 metres are actually rubble piles formed through accumulation of debris after collisions between asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ All units this is General Yamato form a wall between the Glorft and Mendel not a single enemy unit is to get through, am I clear” he ordered.
  • Gundam Legacy, a Gundam Seed fanfic - FanFiction.Net 10 February 2010 11:42 UTC www.fanfiction.net [Source type: Original source]

 ^ In the more distant past, the Datura cluster appears to have formed about 450 million years ago from a collision with a main belt asteroid.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [50]

Kirkwood gaps

Main article: Kirkwood gap
.
This chart shows the distribution of asteroid semi-major axes in the "core" of the main belt.^ Main article: Kirkwood gap This chart shows the distribution of asteroid semi-major axes in the "core" of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt (showing inclinations), with the main belt in red and blue ("core" region in red) Formation .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ "Mass distribution in the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 Cyan arrows point to the Kirkwood gaps, where orbital resonances with Jupiter destabilize orbits.
.The semi-major axis of an asteroid is used to describe the dimensions of its orbit around the Sun, and its value determines the minor planet's orbital period.^ Minor Planet Relatively small celestial bodies composed of metals and rocks that revolve around the sun, a.k.a asteroid and planetoid .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The more complete the sampling of asteroid lightcurves, the better astronomers can develop theories concerning the origin and dynamics of the minor planet system.
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 .In 1866, Daniel Kirkwood announced the discovery of gaps in the distances of these bodies' orbits from the Sun.^ In 1866, Daniel Kirkwood announced the discovery of gaps in the distances of these bodies' orbits from the Sun .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Ceres, Vesta and many thousands of irregular bodies are merely fragments of a planet that once orbited the sun at 2.8.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .They were located at positions where their period of revolution about the Sun was an integer fraction of Jupiter's orbital period.^ They were located at positions where their period of revolution about the Sun was an integer fraction of Jupiter's orbital period.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ When the mean orbital period of an asteroid is an integer fraction of the orbital period of Jupiter, a mean-motion resonance with the gas giant is created that is sufficient to perturb an asteroid to new orbital elements .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Orbital resonances occurred where the orbital period of an object in the belt formed an integer fraction of the orbital period of Jupiter, perturbing the object into a different orbit; the region lying between the orbits of Mars and Jupiter contains many such orbital resonances.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits.^ Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The uncertainties in an asteroid's orbit are greatest in the hours just after its discovery, and thus the calculated probability of an impact also tends to be the highest at these times.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [51]
.When the mean orbital period of an asteroid is an integer fraction of the orbital period of Jupiter, a mean-motion resonance with the gas giant is created that is sufficient to perturb an asteroid to new orbital elements.^ When the mean orbital period of an asteroid is an integer fraction of the orbital period of Jupiter, a mean-motion resonance with the gas giant is created that is sufficient to perturb an asteroid to new orbital elements .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Orbital resonances occurred where the orbital period of an object in the belt formed an integer fraction of the orbital period of Jupiter, perturbing the object into a different orbit; the region lying between the orbits of Mars and Jupiter contains many such orbital resonances.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroid orbits continue to be appreciably perturbed whenever their period of revolution about the Sun forms an orbital resonance with Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Asteroids that become located in the gap orbits (either primordially because of the migration of Jupiter's orbit,[52] or due to prior perturbations or collisions) are gradually nudged into different, random orbits with a larger or smaller semi-major axis.^ In effect, asteroids that become located in the gap orbits (either primordially because of the migration of Jupiter's orbit, [ 52 ] or due to prior perturbations or collisions) are gradually nudged into different, random orbits with a larger or smaller semi-major axis.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Within the main belt, the number distribution of M-type asteroids peaks at a semi-major axis of about 2.7 AU. [ 43 ] It is not yet clear whether all M-types are compositionally similar, or whether it is a label for several varieties which do not fit neatly into the main C and S classes.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Weaker resonances occur at other semi-major axis values, with fewer asteroids found than nearby.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]
.The gaps are not seen in a simple snapshot of the locations of the asteroids at any one time because asteroid orbits are elliptical, and many asteroids still cross through the radii corresponding to the gaps.^ The gaps are not seen in a simple snapshot of the locations of the asteroids at any one time because asteroid orbits are elliptical, and many asteroids still cross through the radii corresponding to the gaps.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Since their orbits cannot be explained through capture of classical comets, it is thought that many of the outer asteroids may be icy, with the ice occasionally exposed to sublimation through small impacts.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ One hundred asteroids had been located by mid-1868, and in 1891 the introduction of astrophotography by Max Wolf accelerated the rate of discovery still further.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The actual spatial density of asteroids in these gaps does not differ significantly from the neighboring regions.^ "The spatial density of asteroids and its variation with asteroidal mass" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The actual spatial density of asteroids in these gaps does not differ significantly from the neighboring regions.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ These are composed primarily of S-type asteroids, whereas the neighboring Hungaria family includes some E-types .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [39]
.The main gaps occur at the 3:1, 5:2, 7:3, and 2:1 mean-motion resonances with Jupiter.^ The main gaps occur at the 3:1, 5:2, 7:3, and 2:1 mean-motion resonances with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU , can be considered the inner boundary of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Cyan arrows point to the Kirkwood gaps, where orbital resonances with Jupiter destabilize orbits.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .An asteroid in the 3:1 Kirkwood gap would orbit the Sun three times for each Jovian orbit, for instance.^ An asteroid in the 3:1 Kirkwood gap would orbit the Sun three times for each Jovian orbit, for instance.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The bacon would be moving slowly at its aphelion and begin its decent toward the sun unless...it smacks into an asteroid (although it should do so at a high speed).
  • Bacon in the Asteroid Belt : Built on Facts 10 February 2010 11:42 UTC scienceblogs.com [Source type: FILTERED WITH BAYES]

 .Weaker resonances occur at other semi-major axis values, with fewer asteroids found than nearby.^ More than 99.8 percent of the 30 000 meteorites found on Earth to date are believed to have originated in the asteroid belt.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ I evaluate fr using a bright star with no others nearby (in the region of the image close to the asteroid).
  • Asteroid Hubting 10 February 2010 11:42 UTC brucegary.net [Source type: FILTERED WITH BAYES]

 (For example, an 8:3 resonance for asteroids with a semi-major axis of 2.71 AU.)[53]
.The main or core population of the asteroid belt is sometimes divided into three zones, based on the most prominent Kirkwood gaps.^ The main or core population of the asteroid belt is sometimes divided into three zones, based on the most prominent Kirkwood gaps.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Zone I lies between the 4:1 resonance (2.06 AU) and 3:1 resonance (2.5 AU) Kirkwood gaps.^ The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Zone III extends from the outer edge of Zone II to the 2:1 resonance gap (3.28 AU).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU , can be considered the inner boundary of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Zone II continues from the end of Zone I out to the 5:2 resonance gap (2.82 AU).^ Zone III extends from the outer edge of Zone II to the 2:1 resonance gap (3.28 AU).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Zone II continues from the end of Zone I out to the 5:2 resonance gap (2.82 AU).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ (Some authors subdivide the inner and outer belts at the 2:1 resonance gap (3.3 AU), while others suggest inner, middle, and outer belts.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Zone III extends from the outer edge of Zone II to the 2:1 resonance gap (3.28 AU).^ Zone III extends from the outer edge of Zone II to the 2:1 resonance gap (3.28 AU).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Zone II continues from the end of Zone I out to the 5:2 resonance gap (2.82 AU).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Skirting the outer edge of the main belt is the Cybele group , orbiting between 3.3 and 3.5 AU. These have a 7:4 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [54]
.The main belt may also be divided into the inner and outer belts, with the inner belt formed by asteroids orbiting nearer to Mars than the 3:1 Kirkwood gap (2.5 AU), and the outer belt formed by those asteroids closer to Jupiter's orbit.^ Main asteroid belt between Mars and Jupiter .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Main belt asteroid with a period of 4.38 years .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 .(Some authors subdivide the inner and outer belts at the 2:1 resonance gap (3.3 AU), while others suggest inner, middle, and outer belts.^ (Some authors subdivide the inner and outer belts at the 2:1 resonance gap (3.3 AU), while others suggest inner, middle, and outer belts.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Zone III extends from the outer edge of Zone II to the 2:1 resonance gap (3.28 AU).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU , can be considered the inner boundary of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 )

Collisions

The zodiacal light, created in part by dust from collisions in the asteroid belt
.The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Main asteroid belt between Mars and Jupiter .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Collisions between main belt bodies with a mean radius of 10 km are expected to occur about once every 10 million years.^ Collisions between main belt bodies with a mean radius of 10 km are expected to occur about once every 10 million years.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Earth about once every 5 years.
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [55] .A collision may fragment an asteroid into numerous smaller pieces (leading to the formation of a new asteroid family).^ A collision may fragment an asteroid into numerous smaller pieces (leading to the formation of a new asteroid family).
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ A September 2007 study by a joint US-Czech team has suggested that a large-body collision undergone by the asteroid 298 Baptistina sent a number of fragments into the inner solar system.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ See the article about the Flora Asteroid Clan which includes an animation of how asteroid families may have formed.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 .Conversely, collisions that occur at low relative speeds may also join two asteroids.^ Conversely, collisions that occur at low relative speeds may also join two asteroids together.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ A collision may fragment an asteroid into numerous smaller pieces (leading to the formation of a new asteroid family).
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ PETER THOMAS: Besides, we may not know enough about asteroids and comets to safely avert a collision.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 .After more than 4 billion years of such processes, the members of the asteroid belt now bear little resemblance to the original population.^ After more than 4 billion years of such processes, the members of the asteroid belt now bear little resemblance to the original population.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In August 2007, a study of zircon crystals in an Antarctic meteorite believed to have originated from 4 Vesta suggested that it, and by extension the rest of the asteroid belt, had formed rather quickly, within ten million years of the Solar System origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
.Along with the asteroid bodies, the main belt also contains bands of dust with particle radii of up to a few hundred micrometres.^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Remove the observational bias towards brighter main belt asteroids.
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ The Main Asteroid Belt is only a small remnant of the material that once resided in the region between Mars and Jupiter, but once may have contained between two to 10 Earth masses of material.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .This fine material is produced, at least in part, from collisions between asteroids, and by the impact of micrometeorites upon the asteroids.^ This fine material is produced, at least in part, from collisions between asteroids, and by the impact of micrometeorites upon the asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Nonetheless, collisions between large asteroids do occur, and these can form an asteroid family whose members have similar orbital characteristics and compositions.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Due to Poynting-Robertson drag, the pressure of solar radiation causes this dust to slowly spiral inward toward the Sun.^ Due to Poynting-Robertson drag , the pressure of solar radiation causes this dust to slowly spiral inward toward the Sun .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Most of the rest of the debris spiralled in and was swallowed by the Sun or was driven out of the solar system.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Vokrouhlicky, D. & A. Milani: Direct solar radiation pressure on the orbits of small near-Earth asteroids: observable effects?
  • Bibliography 10 February 2010 11:42 UTC nai.arc.nasa.gov [Source type: Academic]

 [56]
.The combination of this fine asteroid dust, as well as ejected cometary material, produces the zodiacal light.^ Collisions also produce a fine dust that forms a major component of the zodiacal light.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Collisions also produce a fine dust that forms a major component of the zodiacal light .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The combination of this fine asteroid dust, as well as ejected cometary material, produces the zodiacal light .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .This faint auroral glow can be viewed at night extending from the direction of the Sun along the plane of the ecliptic.^ This faint auroral glow can be viewed at night extending from the direction of the Sun along the plane of the ecliptic .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Particles that produce the visible zodiacal light average about 40 μm in radius.^ Particles that produce the visible zodiacal light average about 40 μm in radius.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The combination of this fine asteroid dust, as well as ejected cometary material, produces the zodiacal light .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Collisions also produce a fine dust that forms a major component of the zodiacal light.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .The typical lifetimes of such particles are about 700,000 years.^ It also will have in 19 years (April 13, 2029) a near Earth rendezvous of about 37,000 kilometers.
  • CR4 - Blog Entry: Russia Plans to Save Earth From Rogue Asteroid 10 February 2010 11:42 UTC cr4.globalspec.com [Source type: FILTERED WITH BAYES]

 ^ About 150,000 Americans every year decide that they do.
  • Ruth Gledhill - Times Online - WBLG: Lesbian Bishop: Archbishop of Canterbury warns of serious questions 10 February 2010 11:42 UTC timescolumns.typepad.com [Source type: Original source]

 .Thus, to maintain the bands of dust, new particles must be steadily produced within the asteroid belt.^ Thus, in order to maintain the bands of dust, new particles must be steadily produced within the asteroid belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Three prominent bands of dust have been found within the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ III - Dust near the asteroid belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [56]

Meteorites

.Some of the debris from collisions can form meteoroids that enter the Earth's atmosphere.^ Some of the debris from collisions can form meteoroids that enter the Earth's atmosphere.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ At the time there was some concern that the debris in the belt would pose a hazard to the spacecraft, but it has since been safely traversed by 9 Earth-based craft without incident.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ According to some models, there was insufficient outgassing of water during the Earth's formative period to form the oceans, necessitating an external source such as a cometary bombardment.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [57] .More than 99.8 percent of the 30,000 meteorites found on Earth to date are believed to have originated in the asteroid belt.^ More than 99.8 percent of the 30,000 meteorites found on Earth to date are believed to have originated in the asteroid belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ More than 99.8 percent of the 30 000 meteorites found on Earth to date are believed to have originated in the asteroid belt.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ In August 2007, a study of zircon crystals in an Antarctic meteorite believed to have originated from 4 Vesta suggested that it, and by extension the rest of the asteroid belt, had formed rather quickly, within ten million years of the Solar System origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [58] .A September 2007 study by a joint US-Czech team has suggested that a large-body collision undergone by the asteroid 298 Baptistina sent a number of fragments into the inner solar system.^ A September 2007 study by a joint US-Czech team has suggested that a large-body collision undergone by the asteroid 298 Baptistina sent a number of fragments into the inner solar system.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Asteroids are not all over the solar system; they are primarily in the gap between Mars and Jupiter.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .The impacts of these fragments are believed to have created both the Tycho crater on the Moon and the Chicxulub crater in Mexico, the remnant of the massive impact which is believed to have triggered the extinction of the dinosaurs 65 million years ago.^ The impacts of these fragments are believed to have created both the Tycho crater on the Moon and the Chicxulub crater in Mexico, the remnant of the massive impact which is believed to have triggered the extinction of the dinosaurs 65 million years ago.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The impacts of these fragments are believed to have created both the Tycho crater on the Moon and the Chicxulub crater in Mexico, the remnant of the massive impact which triggered the extinction of the dinosaurs 65 million years ago.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ We have extensive evidence that Earth has already been hit by asteroids many times throughout history - the most famous (or infamous) example is probably the asteroid or comet that created the Chicxulub crater in the Gulf of Mexico and may have contributed to the extinction of the dinosaurs at the end of the Cretaceous Period 65 million years ago.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [59]

Largest asteroids

See also: Largest asteroids
The dwarf planet Ceres
.Although their location in the asteroid belt excludes them from planet status, the four largest objects, Ceres, Vesta, Pallas, and Hygiea, hover on the edge of hydrostatic equilibrium, the boundary that separates the small solar system object from the dwarf planet.^ The four largest objects, 1 Ceres , 4 Vesta , 2 Pallas and 10 Hygiea , account for half of the belt's total mass, with almost one-third accounted for by Ceres alone.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The asteroids are not samples of the primordial Solar System.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .They share many characteristics common to planets, but also show qualities more akin to rock-like asteroids.^ They share many characteristics common to planets, but also show qualities more akin to rock-like asteroids.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Minor Planet Relatively small celestial bodies composed of metals and rocks that revolve around the sun, a.k.a asteroid and planetoid .
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 ^ Eventually, they were dropped from the planet list as first suggested by Alexander von Humboldt in the early 1850s, and William Herschel's choice of nomenclature, asteroids, gradually came into common use.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]
.Ceres is the only object in the belt large enough for its gravity to force it into a roughly spherical shape, and so, according to the IAU's 2006 resolution on the definition of a planet, it is now considered a dwarf planet.^ Ceres is the only object in the belt large enough for its gravity to force it into a roughly round shape, and so, according to the IAU's 2006 resolution on the definition of a planet, it is now considered a dwarf planet.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Ceres is the only object in the belt large enough for its gravity to force it into a roughly spherical shape, and so, according to the IAU's 2006 resolution on the definition of a planet , it is now considered a dwarf planet .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Although their location in the asteroid belt excludes them from planet status, the four largest objects, Ceres, Vesta, Pallas, and Hygiea, hover on the edge of hydrostatic equilibrium, the boundary that separates objects from planethood.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [60] .The other three may also eventually be reclassified as well.^ The other three may also eventually be reclassified as well.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ As well as the officer primarily concerned with the adventure, any or all of the other three officers may be assigned to the landing party in support.
  • http://tbg.fyndo.com/tbg/Rules.html 10 February 2010 11:42 UTC tbg.fyndo.com [Source type: FILTERED WITH BAYES]

 [61][62] .Ceres has a much higher absolute magnitude than the other asteroids, of around 3.32,[63] and may possess a surface layer of ice.^ Ceres has a much higher absolute magnitude than the other asteroids, of around 3.32, and may possess a surface layer of ice.Like the planets, Ceres is differentiated: it has a crust, a mantle and a core.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Ceres has a much higher absolute magnitude than the other asteroids, of around 3.32, [ 63 ] and may possess a surface layer of ice.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Long term studies of a given asteroid can result in determining the phase coefficients, i.e., the absolute magnitude and slope parameters that define the asteroids brightness especially near opposition when the "opposition effect" causes the asteroid to brighten faster than at larger phase angles.
  • ASTEROID LIGHTCURVES 10 February 2010 11:42 UTC www.asterism.org [Source type: Reference]

 [64] .Like the planets, Ceres is differentiated: it has a crust, a mantle and a core.^ Like the planets, Ceres is differentiated: it has a crust, a mantle and a core.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Ceres has a much higher absolute magnitude than the other asteroids, of around 3.32, and may possess a surface layer of ice.Like the planets, Ceres is differentiated: it has a crust, a mantle and a core.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [64] .Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; [65] its composition is mainly of basaltic rock such as olivine.^ Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; its composition is mainly of basaltic rock such as olivine.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Vesta, too, has a differentiated interior, though it formed inside the Solar System's "snow line", and so is devoid of water; [ 65 ] its composition is mainly of basaltic rock such as olivine.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In August 2007, a study of zircon crystals in an Antarctic meteorite believed to have originated from 4 Vesta suggested that it, and by extension the rest of the asteroid belt, had formed rather quickly, within ten million years of the Solar System origin.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [46] .Pallas is unusual in that, like Uranus, it rotates on its side, with one pole facing the Sun and the other facing away.^ Pallas is unusual in that, like Uranus , it rotates on its side, with one pole facing the Sun and the other facing away.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Pallas is unusual in that, like Uranus, it rotates on its side, with one pole facing the Sun and the other facing away.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ As they were charging the two fleets were still pounding away at one another and every so often ships from either side would be destroyed.
  • Gundam Legacy, a Gundam Seed fanfic - FanFiction.Net 10 February 2010 11:42 UTC www.fanfiction.net [Source type: Original source]

 [66] .Its composition is similar to that of Ceres: high in carbon and silicon.^ Its composition is similar to that of Ceres: high in carbon and silicon.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [67] .Hygiea is a carbonaceous asteroid and, unlike the other largest asteroids, lies relatively close to the plane of the ecliptic.^ Hygiea is a carbonaceous asteroid and, unlike the other largest asteroids, lies relatively close to the plane of the ecliptic .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Hygiea is a carbonaceous asteroid and, unlike the other largest asteroids, lies relatively close to the ecliptic plane.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ One of them is the asteroid belt, which is regularly perturbed by Jupiter in its orbit close to the asteroid belt, and the other one is the so-called Oort Cloud, which is perturbed by the galactic environment.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 [68]

Families and groups

Main article: Asteroid family
This plot of orbital inclination (ip) versus eccentricity (ep) for the numbered main belt asteroids clearly shows several clumps of asteroid families.
.In 1918, the Japanese astronomer Kiyotsugu Hirayama noticed that the orbits of some of the asteroids had similar parameters, forming families or groups.^ See the article about the Flora Asteroid Clan which includes an animation of how asteroid families may have formed.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 ^ Although scientists can calculate a most-likely orbit from these early observations, each single observation of the asteroid's position contains some uncertainty.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Nonetheless, collisions between large asteroids do occur, and these can form an asteroid family whose members have similar orbital characteristics and compositions.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [69]
.Approximately one-third of the asteroids in the main belt are members of an asteroid family.^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Main belt asteroid with a period of 4.38 years .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ The discovery of this second moon makes 45 Eugenia the second asteroid triple, after 87 Sylvia, discovered in the Main Belt between Mars and Jupiter.
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 .These share similar orbital elements, such as semi-major axis, eccentricity, and orbital inclination as well as similar spectral features, all of which indicate a common origin in the breakup of a larger body.^ These share similar orbital elements, such as semi-major axis, eccentricity, and orbital inclination as well as similar spectral features, all of which indicate a common origin in the breakup of a larger body.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Within the main belt, the number distribution of M-type asteroids peaks at a semi-major axis of about 2.7 AU. [ 43 ] It is not yet clear whether all M-types are compositionally similar, or whether it is a label for several varieties which do not fit neatly into the main C and S classes.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Weaker resonances occur at other semi-major axis values, with fewer asteroids found than nearby.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Graphical displays of these elements, for members of the main belt, show concentrations indicating the presence of an asteroid family.^ Graphical displays of these elements, for members of the main belt, show concentrations indicating the presence of an asteroid family.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Asteroid families can be confirmed when the members display common spectral features.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Approximately one third of the asteroids in the main belt are members of an asteroid family.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .There are about 20–30 associations that are almost certainly asteroid families.^ There are about 20–30 associations that are almost certainly asteroid families.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ See the article about the Flora Asteroid Clan which includes an animation of how asteroid families may have formed.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 .Additional groupings have been found that are less certain.^ Additional groupings have been found that are less certain.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Asteroid families can be confirmed when the members display common spectral features.^ Asteroid families can be confirmed when the members display common spectral features.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The largest asteroid to be a true member of a family (as opposed to an interloper in the case of Ceres with the Gefion family ) is 4 Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Graphical displays of these elements, for members of the main belt, show concentrations indicating the presence of an asteroid family.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [70] .Smaller associations of asteroids are called groups or clusters.^ Smaller associations of asteroids are called groups or clusters.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt formed from the primordial solar nebula as a group of planetesimals, the smaller precursors of the planets.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
.Some of the most prominent families in the main belt (in order of increasing semi-major axes) are the Flora, Eunoma, Koronis, Eos, and Themis families.^ Some of the most prominent families in the main belt (in order of increasing semi-major axes) are the Flora , Eunoma , Koronis , Eos , and Themis families.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Graphical displays of these elements, for members of the main belt, show concentrations indicating the presence of an asteroid family.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [43] .The Flora family, one of the largest with more than 800 known members, may have formed from a collision less than a billion years ago.^ Can I have more than one ship?
  • http://tbg.fyndo.com/tbg/Rules.html 10 February 2010 11:42 UTC tbg.fyndo.com [Source type: FILTERED WITH BAYES]

 ^ The Flora family, one of the largest with more than 800 known members, may have formed from a collision less than a billion years ago.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The largest asteroid to be a true member of a family (as opposed to an interloper in the case of Ceres with the Gefion family ) is 4 Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [71] .The largest asteroid to be a true member of a family (as opposed to an interloper in the case of Ceres with the Gefion family) is 4 Vesta.^ The largest asteroid to be a true member of a family (as opposed to an interloper in the case of Ceres with the Gefion family ) is 4 Vesta.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Although their location in the asteroid belt excludes them from planet status, the four largest objects, Ceres, Vesta, Pallas, and Hygiea, hover on the edge of hydrostatic equilibrium, the boundary that separates objects from planethood.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ See also: Largest asteroids The dwarf planet Ceres Although their location in the asteroid belt excludes them from planet status, the four largest objects, Ceres , Vesta , Pallas , and Hygiea , hover on the edge of hydrostatic equilibrium , the boundary that separates the small solar system object from the dwarf planet .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The Vesta family is believed to have formed as the result of a crater-forming impact on Vesta.^ Impact craters are geologic structures formed when a large meteoroid, asteroid or comet smashes into a planet or a satellite.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ ALEX BEVAN: In Australia, we have a group of thirteen craters that was formed by an impact of a large iron meteorite around about five thousand years ago.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 ^ The central peak or peak ring of the complex crater is formed as the initial (transient) deep crater floor rebounds from the compressional shock of impact.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .Likewise, the HED meteorites may also have originated from Vesta as a result of this collision.^ Likewise, the HED meteorites may also have originated from Vesta as a result of this collision.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [72]
.Three prominent bands of dust have been found within the main belt.^ Three prominent bands of dust have been found within the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.^ These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Categories : Asteroid groups and families .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1918, the Japanese astronomer Kiyotsugu Hirayama noticed that the orbits of some of the asteroids had similar parameters, forming families or groups.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [73]

Periphery

.Skirting the inner edge of the belt (ranging between 1.78 and 2.0 AU, with a mean semi-major axis of 1.9 AU) is the Hungaria family of minor planets.^ "The Hungaria group of minor planets" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Skirting the inner edge of the belt (ranging between 1.78 and 2.0 AU, with a mean semi-major axis of 1.9 AU) is the Hungaria family of minor planets.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .They are named after the main member, 434 Hungaria; the group contains at least 52 named asteroids.^ They are named after the main member, 434 Hungaria ; the group contains at least 52 named asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Graphical displays of these elements, for members of the main belt, show concentrations indicating the presence of an asteroid family.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Accordingly, in 1802 William Herschel suggested they be placed into a separate category, named asteroids, after the Greek asteroeides , meaning "star-like".
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The Hungaria group is separated from the main body by the 4:1 Kirkwood gap and their orbits have a high inclination.^ At these orbital distances, a Kirkwood gap occurs as they are swept into other orbits.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ Due to the high inclination of Varsavia's orbit (29), the 80 km wide path was mainly north-south.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 .Some members belong to the Mars-crossing category of asteroids, and gravitational perturbations by Mars are likely a factor in reducing the total population of this group.^ Some members belong to the Mars-crossing category of asteroids, and gravitational perturbations by Mars are likely a factor in reducing the total population of this group.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Categories : Asteroid groups and families .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [74]
.Another high-inclination group in the inner part of the main belt is the Phocaea family.^ Another high-inclination group in the inner part of the main belt is the Phocaea family .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The zodiacal light , created in part by dust from collisions in the asteroid belt The high population of the main belt makes for a very active environment, where collisions between asteroids occur frequently (on astronomical time scales).
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ These have similar orbital inclinations as the Eos, Koronis, and Themis asteroid families, and so are possibly associated with those groupings.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .These are composed primarily of S-type asteroids, whereas the neighboring Hungaria family includes some E-types.^ See the article about the Flora Asteroid Clan which includes an animation of how asteroid families may have formed.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 [75] .The Phocaea family orbit between 2.25 and 2.5 AU from the Sun.^ The Phocaea family orbit between 2.25 and 2.5 AU from the Sun.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Nysa is also the largest asteroid of a family consisting of 381 members situated in the range of 2.419 - 2.477 AU's from the Sun.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]
.Skirting the outer edge of the main belt is the Cybele group, orbiting between 3.3 and 3.5 AU. These have a 7:4 orbital resonance with Jupiter.^ The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU , can be considered the inner boundary of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The main asteroid belt (shown in white) is located between the orbits of Mars and Jupiter .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.^ The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Phocaea family orbit between 2.25 and 2.5 AU from the Sun.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ There are few asteroids beyond 4.2 AU, until Jupiter's orbit.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .There are few asteroids beyond 4.2 AU, until Jupiter's orbit.^ There are few asteroids beyond 4.2 AU, until Jupiter's orbit.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The Hilda family orbit between 3.5 and 4.2 AU, and have relatively circular orbits and a stable 3:2 orbital resonance with Jupiter.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Here the two families of Trojan asteroids can be found, which are approximately as numerous as the asteroids of the main belt.^ "Two new basaltic asteroids in the Outer Main Belt" .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Approximately one third of the asteroids in the main belt are members of an asteroid family.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Here the two families of Trojan asteroids can be found, which are approximately as numerous as the asteroids of the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [76]

New families

.Some asteroid families have formed recently, in astronomical terms.^ Some asteroid families have formed recently, in astronomical terms.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In 1918, the Japanese astronomer Kiyotsugu Hirayama noticed that the orbits of some of the asteroids had similar parameters, forming families or groups.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ See the article about the Flora Asteroid Clan which includes an animation of how asteroid families may have formed.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 .The Karin Cluster apparently formed about 5.7 million years ago from a collision with a 16 km radius progenitor asteroid.^ It was probably formed approximately 300 million years ago.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ ALEX BEVAN: In Australia, we have a group of thirteen craters that was formed by an impact of a large iron meteorite around about five thousand years ago.
  • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

 ^ Space probes can image asteroids directly, but this takes years and hundreds of millions of dollars plus the usual delays and funding cuts by Congress.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 [77] .The Veritas family formed about 8.3 million years ago; evidence includes interplanetary dust recovered from ocean sediment.^ The Veritas family formed about 8.3 million years ago; evidence includes interplanetary dust recovered from ocean sediment.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ It was probably formed approximately 300 million years ago.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ At the current rate of impacts, we would expect about one large asteroid to impact Earth every 100 million years or so.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 [78]
.In the more distant past, the Datura cluster appears to have formed about 450 million years ago from a collision with a main belt asteroid.^ Main belt asteroid with a period of 4.38 years .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 ^ In the more distant past, the Datura cluster appears to have formed about 450 million years ago from a collision with a main belt asteroid.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Main belt asteroid with a period of 4.09 years .
  • Table of contents 10 February 2010 11:42 UTC www.britastro.org [Source type: Academic]

 .The age estimate is based on the probability of the members having their current orbits, rather than from any physical evidence.^ The age estimate is based on the probability of the members having their current orbits, rather than from any physical evidence.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ While large empires are possible, they must be controlled with skill and diplomacy rather than just by having a lot of warships.
  • http://tbg.fyndo.com/tbg/Rules.html 10 February 2010 11:42 UTC tbg.fyndo.com [Source type: FILTERED WITH BAYES]

 ^ A huge planet, larger than Jupiter, going around our sun, is probably far beyond the orbit of Pluto.
  • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 .However, this cluster may have been a source for some zodiacal dust material.^ However, this cluster may have been a source for some zodiacal dust material.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Other recent cluster formations, such as the Iannini cluster ( circa 1–5 million years ago), may have provided additional sources of this asteroid dust.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The combination of this fine asteroid dust, as well as ejected cometary material, produces the zodiacal light .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [79] .Other recent cluster formations, such as the Iannini cluster (circa 1–5 million years ago), may have provided additional sources of this asteroid dust.^ Other recent cluster formations, such as the Iannini cluster ( circa 1–5 million years ago), may have provided additional sources of this asteroid dust.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ However, this cluster may have been a source for some zodiacal dust material.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Space probes can image asteroids directly, but this takes years and hundreds of millions of dollars plus the usual delays and funding cuts by Congress.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 [80]

Exploration

Artist's concept of the Dawn Mission spacecraft with Vesta (left) and Ceres (right)
.The first spacecraft to traverse the asteroid belt was Pioneer 10, which entered the region on July 16, 1972. At the time there was some concern that the debris in the belt would pose a hazard to the spacecraft, but it has since been safely traversed by 9 Earth-based craft without incident.^ Some of the debris from collisions can form meteoroids that enter the Earth's atmosphere.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Artist's concept of the Dawn Mission spacecraft with Vesta (left) and Ceres (right) The first spacecraft to traverse the asteroid belt was Pioneer 10 , which entered the region on July 16, 1972.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ At the time there was some concern that the debris in the belt would pose a hazard to the spacecraft, but it has since been safely traversed by 9 Earth-based craft without incident.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Pioneer 11, Voyagers 1 and 2 and Ulysses passed through the belt without imaging any asteroids.^ Pioneer 11 , Voyagers 1 and 2 and Ulysses passed through the belt without imaging any asteroids.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The Main Belt Zone II type "T" asteroid 114 Kassandra occulted a m = 11.8 star on December 21, 2003 over the United States.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 ^ While there is nothing to prevent a new comet from the Oort cloud, or one of the residents of the asteroid belt to stumble into a trajectory that will impact us on the first pass.
  • CR4 - Blog Entry: Russia Plans to Save Earth From Rogue Asteroid 10 February 2010 11:42 UTC cr4.globalspec.com [Source type: FILTERED WITH BAYES]

 .Galileo imaged the asteroid 951 Gaspra in 1991 and 243 Ida in 1993, NEAR imaged 253 Mathilde in 1997, Cassini imaged 2685 Masursky in 2000, Stardust imaged 5535 Annefrank in 2002, New Horizons imaged 132524 APL in 2006, and Rosetta imaged 2867 Šteins in 2008.[81] Due to the low density of materials within the belt, the odds of a probe running into an asteroid are now estimated at less than one in a billion.^ And to date, less than 5 asteroids have been imaged by space probes.
  • Asteroid_News.htm 10 February 2010 11:42 UTC weblore.com [Source type: General]

 ^ Galileo imaged the asteroid 951 Gaspra in 1991 and 243 Ida in 1993, NEAR imaged 253 Mathilde in 1997, Cassini imaged 2685 Masursky in 2000, Stardust imaged 5535 Annefrank in 2002, New Horizons imaged 132524 APL in 2006, and Rosetta imaged 2867 Šteins in 2008.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Due to the low density of materials within the belt, the odds of a probe running into an asteroid are now estimated at less than one in a billion.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 [82]
.All spacecraft images of belt asteroids to date have come from brief flyby opportunities by probes headed for other targets.^ All spacecraft images of belt asteroids to date have come from brief flyby opportunities by probes headed for other targets.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The asteroid belt region is also termed the main belt to distinguish it from other concentrations of minor planets within the Solar System, such as the Kuiper belt and scattered disc.
  • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

 ^ The expression "asteroid belt" comes into use in the very early 1850s, although it is hard to pinpoint who coined the term.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .Only the NEAR and Hayabusa missions have studied asteroids for a protracted period in orbit and at the surface and these were near-Earth asteroids.^ Only the NEAR and Hayabusa missions have studied asteroids for a protracted period in orbit and at the surface and these were near-Earth asteroids .
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Gehrels, T.: A proposal to the United Nations regarding the international discovery programs of near-Earth asteroids.
  • Bibliography 10 February 2010 11:42 UTC nai.arc.nasa.gov [Source type: Academic]

 ^ Kozai, Y.: Dynamical behaviour of Earth orbit crossing asteroids.
  • Bibliography 10 February 2010 11:42 UTC nai.arc.nasa.gov [Source type: Academic]

 .However, the Dawn Mission has been dispatched to explore Vesta and Ceres in the main belt.^ However, the Dawn Mission has been dispatched to explore Vesta and Ceres in the main belt.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ Artist's concept of the Dawn Mission spacecraft with Vesta (left) and Ceres (right) The first spacecraft to traverse the asteroid belt was Pioneer 10 , which entered the region on July 16, 1972.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ The four largest objects, 1 Ceres , 4 Vesta , 2 Pallas and 10 Hygiea , account for half of the belt's total mass, with almost one-third accounted for by Ceres alone.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 .If the probe is still operational after examining these two large bodies, an extended mission is possible that could allow additional exploration.^ If the probe is still operational after examining these two large bodies, an extended mission is possible that could allow additional exploration.
  • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

 ^ In addition, it will open some new possibilities for more distant manned missions.
  • ksl.com - Russia may send spacecraft to knock away asteroid 10 February 2010 11:42 UTC www.ksl.com [Source type: Original source]

 ^ The PererB raft of extended possibilities allow for this of course in the 'Frequently Asked Questions' section.
  • Ruth Gledhill - Times Online - WBLG: Lesbian Bishop: Archbishop of Canterbury warns of serious questions 10 February 2010 11:42 UTC timescolumns.typepad.com [Source type: Original source]

 [83]

See also

References

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Further reading

.
  • Elkins-Tanton, Linda T. (2006).^ Elkins-Tanton, Linda T. (2006).
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     .Asteroids, Meteorites, and Comets (First ed.^ Asteroids, Meteorites, and Comets (First ed.
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ This is the first time ever that anyone had attempted to go and systematically survey the space near the earth for earth-crossing bodies, asteroids and comets that could hit the earth.
    • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

     ^ While there is nothing to prevent a new comet from the Oort cloud, or one of the residents of the asteroid belt to stumble into a trajectory that will impact us on the first pass.
    • CR4 - Blog Entry: Russia Plans to Save Earth From Rogue Asteroid 10 February 2010 11:42 UTC cr4.globalspec.com [Source type: FILTERED WITH BAYES]

     ). New York: Chelsea House. ISBN 0-8160-5195-X. 

External links

.
  • Arnett, William A. (February 26, 2006).^ Arnett, William A. (February 26, 2006).
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     "Asteroids". The Nine Planets. .http://www.nineplanets.org/asteroids.html.^ List of impact craters on Earth (Wikipedia) http://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth Earth Impact Database: http://www.unb.ca/passc/ImpactDatabase/ http://www.unb.ca/passc/ImpactDatabase/CINameSort2.htm http://www.mnh.si.edu/earth/text/5_3_4_2.html http://en.wikipedia.org/wiki/Meteor_Crater .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Source: http://www.agu.org/sci_soc/sharpton.html .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Asteroids Page at NASA's Solar System Exploration http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/ "Main-Belt Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     .Retrieved 2007-04-20.     
  • Asteroids Page at NASA's Solar System Exploration
  • Fraser Cain.^ Retrieved 2007-04-10 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Retrieved 2007-04-11 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ The asteroids are not samples of the primordial Solar System.
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     "The Asteroid Belt". Universe Today. .http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/.^ Read more: http://www.world-mysteries.com/mpl_10.htm#Mexico .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Asteroids Page at NASA's Solar System Exploration http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/ "Main-Belt Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Asteroid Belt - includes info about Exploded Planet Thery and Bode's Law Tunguska Event http://www.world-mysteries.com/dougy_tunguska.htm External Links .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     Retrieved 2008-04-01    . 
  • Hsieh, Henry H. (March 1, 2006). ."Main-Belt Comets".^ Main article: Main-belt comet Several otherwise unremarkable bodies in the outer belt show cometary activity.
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Meteoroids · Minor planets ( Asteroids ( Main belt ) · Centaurs · TNOs ( Kuiper belt · Scattered disc ) ) · Comets ( Oort cloud ) .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Asteroids Page at NASA's Solar System Exploration http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/ "Main-Belt Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     University of Hawaii. .http://www.ifa.hawaii.edu/~hsieh/mbcs.html.^ List of impact craters on Earth (Wikipedia) http://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth Earth Impact Database: http://www.unb.ca/passc/ImpactDatabase/ http://www.unb.ca/passc/ImpactDatabase/CINameSort2.htm http://www.mnh.si.edu/earth/text/5_3_4_2.html http://en.wikipedia.org/wiki/Meteor_Crater .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Source: http://www.agu.org/sci_soc/sharpton.html .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ The Mysterious Bermuda Triangle - http://www.cat.cc.md.us/~mpowers/tmbt.html .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     .Retrieved 2007-04-20.     
  • "Main Asteroid Belt".^ Retrieved 2007-04-10 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Retrieved 2007-04-11 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Meteoroids · Minor planets ( Asteroids ( Main belt ) · Centaurs · TNOs ( Kuiper belt · Scattered disc ) ) · Comets ( Oort cloud ) .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     Sol Company. .http://www.solstation.com/stars/asteroid.htm.^ Read more: http://www.world-mysteries.com/mpl_10.htm#Mexico .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Asteroids Page at NASA's Solar System Exploration http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/ "Main-Belt Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Continental movement, plate tectonics, continental drift, geophysics, earth http://www.aaronc.com/pelgnet/pelchap6/Chap6.html .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     .Retrieved 2007-04-20.     
  • Munsell, Kirk (September 16, 2005).^ Retrieved 2007-04-10 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Retrieved 2007-04-11 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Retrieved 2007-04-26 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     .Asteroids Page "Asteroids: Overview".^ Asteroids Page "Asteroids: Overview" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     .NASA's Solar System Exploration.^ Asteroids Page at NASA's Solar System Exploration http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/ "Main-Belt Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ NASA's Solar System Exploration .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ That water (off of Earth) could be critical in the solar system exploration you (and I) advocate.
    • ksl.com - Russia may send spacecraft to knock away asteroid 10 February 2010 11:42 UTC www.ksl.com [Source type: Original source]

     .http://solarsystem.nasa.gov/planets/profile.cfm?Object=Asteroids Asteroids Page.^ Asteroids Page at NASA's Solar System Exploration http://www.astronomycast.com/astronomy/episode-55-the-asteroid-belt/ "Main-Belt Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     Retrieved 2007-05-26    . 
  • Plots of eccentricity vs. semi-major axis and inclination vs. semi-major axis at Asteroid Dynamic Site
  • Staff (October 31, 2006). "Asteroids". NASA. .http://nssdc.gsfc.nasa.gov/planetary/planets/asteroidpage.html.^ (Here is a link to a cool pic)http://antwrp.gsfc.nasa.gov/apod/ap990109.html I am sick of retarded people like yourself making stupid and pointless arguments about us never going to the moon with stupid arguments and ignoring simple, and irrefutable facts like this.
    • ksl.com - Russia may send spacecraft to knock away asteroid 10 February 2010 11:42 UTC www.ksl.com [Source type: Original source]

     ^ ImpactDatabase/essay.html http://www.esa.int/esaSC/SEMOHJAMS7F_index_0.html Planetary Maps: http://laps.noaa.gov/albers/sos/sos.html#MERCURY http://pdsmaps.wr.usgs.gov/PDS/public/explorer/html/mmfront.htm http://www.mapaplanet.org/ http://neo.jpl.nasa.gov/ .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     .Retrieved 2007-04-20.     
  • Staff (2007).^ Retrieved 2007-04-10 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Retrieved 2007-04-11 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ Retrieved 2007-04-26 .
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ."Space Topics: Asteroids and Comets".^ "Space Topics: Asteroids and Comets" .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]
    • Boston University School of Theology Archives 10 February 2010 11:42 UTC sthweb.bu.edu [Source type: Academic]

     ^ This is the first time ever that anyone had attempted to go and systematically survey the space near the earth for earth-crossing bodies, asteroids and comets that could hit the earth.
    • NOVA | Transcripts | The Doomsday Asteroid | PBS 10 February 2010 11:42 UTC www.pbs.org [Source type: Original source]

     ^ Planetary Space Science 46:219-229 (1998) Hills, J.C. and P. Goda: Tsunami from asteroid and comet impacts: The vulnerability of Europe.
    • Bibliography 10 February 2010 11:42 UTC nai.arc.nasa.gov [Source type: Academic]

     The Planetary Society. .http://www.planetary.org/explore/topics/asteroids_and_comets/facts.html.^ List of impact craters on Earth (Wikipedia) http://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth Earth Impact Database: http://www.unb.ca/passc/ImpactDatabase/ http://www.unb.ca/passc/ImpactDatabase/CINameSort2.htm http://www.mnh.si.edu/earth/text/5_3_4_2.html http://en.wikipedia.org/wiki/Meteor_Crater .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Source: http://www.agu.org/sci_soc/sharpton.html .
    • Earth - a Moving Target. Asteroids, Craters, impacts, Gulf of Mexico, Extinction and more... 17 September 2009 0:32 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     ^ Related Link: http://www.metaresearch.org/solar%20system/eph/eph2000.asp .
    • Science Mysteries - Asteroid Belt - The Exploded Planet Hypothesis (EPH) - Tunguska asteroid impact 10 February 2010 11:42 UTC www.world-mysteries.com [Source type: FILTERED WITH BAYES]

     Retrieved 2007-04-20    . 
Small Solar System bodies
Lists: Asteroid groups and families · Asteroid moons · Binary asteroids · Minor planets
See also: Dwarf planet, Meanings of minor planet names, Planet, Pronunciation of asteroid names, and Solar System
The Solar System
The Sun Mercury Venus The Moon Earth Mars Phobos and Deimos Ceres The main asteroid belt Jupiter Moons of Jupiter Rings of Jupiter Saturn Moons of Saturn Rings of Saturn Uranus Moons of Uranus Rings of Uranus Neptune Moons of Neptune Rings of Neptune Pluto Moons of Pluto Haumea Moons of Haumea Makemake The Kuiper Belt Eris Dysnomia The Scattered Disc The Hills Cloud The Oort Cloud Solar System Template Final.png
Related articles: astronomical object, star, planet, dwarf planet, small body and planetary system
See also the Solar System's list of objects, sorted by size, the list of minor planets, or the Solar System Portal

Simple English

Simple English Wiktionary has the word meaning for:

The asteroid belt or main belt is a ring of small and large rocks and dust between the orbits of Mars and Jupiter. The biggest object in the asteroid belt is Ceres, a dwarf planet. Most asteroids orbit at 2 to 3 times the distance between Earth and the Sun. Planets that are "inside" - or before - the asteroid belt (which means they are closer to the sun) are called inner planets. Planets that are "outside" - that is, after - the asteroid belt are called outer planets: so Mercury, Venus, earth, and Mars are inner planets, while Jupiter, Saturn, Uranus, Neptune and Pluto are the outer planets.

Origin

This article contains weasel words, vague phrasing that often accompanies biased or unverifiable information. Such statements should be clarified or removed.

The asteroid belt looks a lot like the orbit of a planet. There may be a reason for this. There is some evidence that there used to be a planet that orbited the sun between Mars and Jupiter.[needs proof] It might have exploded, and the asteroids in the asteroid belt may be the remains of that planet.

The idea that there was once a planet between Mars and Jupiter that exploded to become the asteroid belt is called the Exploded Planet Hypothesis (a hypothesis is an idea that may or may not be true). The Exploded Planet Hypothesis has several reasons to support it. Firstly, if a terrestrial planet exploded, pieces that flew into space would look like rocks and ice.[needs proof] Our planet is made of mostly water, so if it exploded, it would send millions of tons of water into space, and this water would become ice, maybe making really big comets.[1]

More reasons that might support this hypothesis are the crater scars on many planets and moons. When a very large meteorite hits a planet or a moon, it leaves a crater (a big dent in the surface). However, some scientists argue that the meteroites hit the planets and moons randomly over many, many years, and some say that the Exploded Planet Hypothesis could not be true because there are not enough asteroids in the asteroid belt to make up a whole planet. Those who think the Exploded Planet Hypothesis is true, however, say that if all the comets and other objects in the solar system that look like they come from a planet were counted, this exploded planet would be much bigger than the earth.[2]

Formation

The asteroid belt failed to form a planet because of Jupiter's gravity. The belt used to contain many more asteroids than it does today, but Jupiter's gravity disturbed the orbiting debris and much of it was sent into orbits which meant it was lost to the asteroid belt. The total mass of the material in the asteroid belt today is thought to be about 4% of the mass of the Earth's Moon.

References

  1. ↑ Exploring Creation with Astronomy by Jeannie K. Fulbright p.98
  2. ↑ Exploring Creation with Astronomy by Jeannie K. Fulbright p.99
[[Template:FULLPAGENAME: Solar System|v]] • [[{{TALKPAGENAME:Template:FULLPAGENAME: Solar System}}|d]] • [{{fullurl:Template:FULLPAGENAME: Solar System|action=edit}}e]
The Solar System
Sun
•
Heliosphere
 Planets
☾ = moon(s) ∅ = rings		 Mercury Venus Earth ☾ Mars ☾
Jupiter ☾ ∅ Saturn ☾ ∅ Uranus ☾ ∅ Neptune ☾ ∅  
Dwarf planets Ceres Pluto ☾ Haumea ☾ Makemake
Eris ☾
Small
Solar
System
bodies		Asteroids
(minor planets) 		Groups and families: Vulcanoids · Near-Earth asteroids · Asteroid belt
Jupiter Trojans · Centaurs · Neptune Trojans · Asteroid moons · Meteoroids · Pallas · Juno · Vesta · Hygiea ·
See also the list of asteroids, and the meaning and pronunciation of asteroid names.
Trans-
Neptunians 		Kuiper belt – Plutinos: Orcus · Ixion – Cubewanos: 556372002 UX · Varuna ·
15760 1992 QB · 556362002 TX · Quaoar · Huya · 555652002 AW
Scattered disc: 845222002 TC · 2004 XR190 · Sedna
Comets Lists of periodic and non-periodic comets · Damocloids · Hills cloud · Oort cloud
See also Geology of solar terrestrial planets, astronomical objects, the solar system's list of objects, sorted by radius or mass, and the Solar System Portal

Retrieved from "http://yak.rapint.com/wiki/Asteroid_belt"

Citable sentences

Up to date as of December 18, 2010

Here are sentences from other pages on Asteroid belt, which are similar to those in the above article.








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