Space science is an all-encompassing term that describes all of the various science fields that are concerned with the study of the Universe, generally also meaning "excluding the Earth" and "outside of the Earth's atmosphere". Originally, all of these fields were considered part of astronomy. However, in recent years the major sub-fields within astronomy, such as astrophysics, have grown so large that they are now considered separate fields on their own. There are eight overall categories that can generally be described on their own; Astrophysics, Galactic Science, Stellar Science, non-Earth Planetary Science, Biology of Other Planets, Astronautics/Space Travel, Space Colonization and Space Defense. The Library of Congress and Dewey Decimal System have a major classification "Descriptive Astronomy" which they use instead of placing descriptive works into their huge "Geography" collections.
Astronomical methods are the equipment and techniques used to collect data about the objects in Space. Galileo's first astronomical method was to find and buy the best telescope of the time and then point that telescope to the heavens. Methods can be categorized according to the wavelength they are attempting to record.
Radio astronomy includes radio telescopes; devices that receive and record radio waves from outside the Earth. They record cosmic microwave background radiation resulting from the Big Bang, Pulsars and other sources. Optical astronomy is the oldest kind of astronomy. X-ray observatories include the Chandra X-ray Observatory and others. gamma ray includes the Compton Gamma Ray Observatory and others. Neutrino astronomy observatories have also been built, primarily to study our Sun. Gravitational wave observatories have been theorized.
A space telescope is a telescope orbiting or travelling from the Earth, such as the Hubble space telescope. RXTE is Long Exposure Time Astronomy used to study millisecond pulsars and pulsar deceleration.
Astronomy teaching tools include Planetariums and others.
Further information can be found at Library of Congress Classification QB1-139 General Astronomy (Dewey 520), QB140-237 Practical and spherical astronomy (Dewey 522), (Observatories Dewey 522), QB468-480 Non-optical methods of astronomy
Galileo's second astronomical method was to describe what he saw in the telescope. Descriptive Astronomy is the highest sub-category of Astronomy used by the Library of Congress and Dewey Decimal systems to classify any knowledge related to describing celestial objects. Because we are seeing today portions of the Universe as they actually looked millions or billions of years ago we should have a historical section within Descriptive astronomy: History of The Universe includes the size, shape and structure of the historical universe), Cartography of The Historical Universe, Early Universe and others. The Current Universe includes size shape and structure of the current Universe, cartography of the current Universe and others.
Cartography of Space Bodies. Recording photographic or similar images of the Earths surface from space is a well developed science, yet still expanding because of advances in the actual resolution of images taken from space or atmosphere and because of advances in digitizing and manipulating the images. Most of these advances are being applied to the cartography of space-located bodies, even though acquiring the original images of those bodies is extremely complicated and expensive, usually requiring long distance probes to carry the cameras. Further information is available at Library of Congress Classification: G3190-3191 Celestial maps.
Visible matter in the universe is apparently organized geographically into structures with large amounts of space between them; either the space between planets, the space between stars or the space between galaxies. Even galaxies themselves are not spread uniformly but appear to be located in filaments. Therefore The Universe can be divided geographically into regions that follow this structure The Filaments of Galaxies are the furthest visible structures.
Those filaments are made of superclusters, tending to line up in filaments. Our Milky Way Galaxy is a galaxy in what is called the Our Supercluster of Galaxies by the National Geographic Society. Some 150 million light-years across, Our Supercluster is a great aggregation of perhaps thousands of smaller clusters of galaxies. The largest of these smaller clusters is called the Virgo Cluster. According to National Geographic, The Virgo Cluster contains the center of mass of Our Supercluster. Although The Milky Way Galaxy is a part of Our Supercluster, it is not a part of the Virgo Cluster. Our Milky Way Galaxy is part of a cluster called the Local Group. Gravitationally, our Local Group plays a small role in Our Supercluster because it is a small and distant cluster from the center. A much larger cluster within in Our Supercluster is the Ursa Major Cluster. The following objects are located within Our Supercluster but not within the Local Group; they are objects 100,000,000 light-years to 10,000,000 light-years from the Sun: M49, M51, M58, M59, M60, M61, M63, M64, M65, M66. National Geographic magazine has produced a very good drawing of this region in its Map of the Universe Supplement, October 1999 issue.
Local Group: Our Milky Way Galaxy is one of about 30 galaxies called the Local Group. The Local Group is about 4 million light-years across. In the Local Group our Milky Way Galaxy plays a large gravitational part because our galaxy is the second largest galaxy in our Local Group, second only to the Andromeda Galaxy. All of the other galaxies in our Local Group are gravitationally bound either to the Andromeda Galaxy or to our Milky Way Galaxy. Inside of our local group but outside of our Galaxy are objects 4,000,000 LY to 1,000,000 LY from the Sun: M31, M32, M33.
Milky Way Galaxy: Our Milky Way Galaxy is a massive mass-containing structure 100,000 light-years across and 30,000 light-years tall. Most of its billions of suns are organized into several structures called "arms". Our Sun is located in what is called the "Orion Arm". The next arm outside of us is called the "Perseus Arm". The Crab Nebula M1 is located in the Perseus Arm. The arm outside of the Perseus Arm is called the Outer Arm. Palomar 1 is located in the Outer Arm. The next arm inside of us is called the Sagittarius Arm. The Ring Nebula M57 and the Carina Nebula (NGC 3372) are located in the Sagittarius Arm. The next arm inside of the Sagittarius Arm is called the Crux Arm. The inner arms are much shorter, obviously from being shifted by gravitational forces. Arms beside each other today may have at an earlier time been one.
Orion Arm: The Orion Nebula M42 is located in our Arm. Celestial Objects 1000 LY to 100 LY from the Sun: M39, M44, M45. Celestial Objects 100 LY to 16LY From the Sun. Celestial Objects less than 16 LY from the Sun: List of nearest stars
Nearby-Stars Solar Systems: By measuring the extremely small movements of nearby stars astronomers have been able to prove that there are planets going around these Suns, therefore these suns have become "Solar Systems".
Further reading can be found in the Library of Congress Classification QB495-903 Descriptive astronomy (Dewey 523) Galileo's second astronomical method was to describe what he saw in the telescope.
After first looking at the planets, then second describing what he saw, Galileo's third astronomical method was to theorize about the reasons for what he saw in the telescope, specifically to theorize that the Earth goes around the Sun. The Physics of the Universe can be divided into several broad categories:
Astrophysical Theory includes general relativity and others.
Astrophysical Processes includes baryonic and others.
Origins Of The Universe Universe Theories of the Origins of the Universe, Big Bang Theory, Early Universe, Evidence, Cosmic Microwave Background, Dark Ages, Interstellar Medium , voids, Filaments of Galaxies, galaxy clusters and others.
Cosmic Plasmas Between Stars, (Diffuse Plasmas) includes intergalactic space, intergalactic medium, interstellar medium, interplanetary medium, heliospheric current sheet, interplanetary medium, Solar wind and others.
Cosmic Plasmas Inside Stars, (Dense Plasma) includes Stars, plasma physicists, active galactic nuclei, fusion power, magnetohydrodynamic, X-rays , bremsstrahlung, Cosmology , reionized, ambipolar diffusion, Particle Physics and others.
Further information can be found at Library of Congress Classification QB460-466 Astrophysics, QB349-421 Theoretical astronomy and celestial mechanics, and QB980-991 Cosmogony. Cosmology (PHYSICAL COSMOLOGY ONLY), (Dewey "Theoretical Astronomy" 521)
Physics can explain the underlying physical science of any galaxy, yet many aspects of galaxies are not best described through their physics. Galactic physical science is the general term for all physical sciences that can be applied to any galaxy in the Universe or to a particular galaxy.
Intra-Galaxy Processes, General includes Black Hole, Globular Clusters, Satellite Galaxy, Retrograde Rotation, Halo stars, High Velocity Clouds, Monoceros Ring, accretion disc, Gravitation, Angular momentum, Centripetal force, tidal effects, Viscosity, orbital momentum, Accretion disk, Active galactic nuclei, Protoplanetary discs, Gamma ray bursts and others.
Milky Way Galactic Physical Science is the overall science containing all the physical sciences related directly to the Milky Way Galaxy: Halo stars, Milky Way High Velocity Clouds, Milky Way Monoceros Ring, Milky Way accretion disc, Milky Way Gravitation, Milky Way Angular momentum, Milky Way Centripetal force, Milky Way tidal effects, Milky Way Viscosity, Milky Way orbital momentum, Milky Way event horizon, Milky Way black hole and others.
Physics is the underlying physical science of any star, yet many aspects of stars are not best described through their physics. Stellar science is the general term for ALL physical sciences that can be applied to any star in the Universe or to a particular star. Solar science of the Sun Sun is the overall science containing all of the physical sciences related directly to our local Sun.
Stellar-Processes, General Stellar dynamics, stars, Stellar Evolution, event horizon, black hole, x-rays, nuclear fusion and others. In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime; the hundreds of thousands, millions or billions of years during which it emits light and heat. Over the course of that time, the star will change radically.
Stellar evolution is not studied by observing the life cycle of a single star—most stellar changes occur too slowly to be detected even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars, each at a different point in its life cycle, and simulating stellar structure with computer models.
Birth of stars is discussed in Main article: Star Formation
Stellar evolution begins with a giant molecular cloud (GMC), also known as a stellar nursery. Most of the 'empty' space inside a galaxy actually contains around 0.1 to 1 particle per cm³, but inside a GMC, the typical density is a few million particles per cm³. A GMC contains 100,000 to 10,000,000 times as much mass as our Sun by virtue of its size: 50 to 300 light-years across.
Very small protostars never reach temperatures high enough for nuclear fusion of hydrogen to begin; these are brown dwarfs of less than 0.1 solar mass. Brown dwarfs heavier than 13 Jupiter masses (MJ) do fuse deuterium, and some astronomers prefer to call only these objects brown dwarfs, classifying anything larger than a planet but smaller than this a sub-stellar object. Both types, deuterium-burning or not, shine dimly and die away slowly, cooling gradually over hundreds of millions of years. The central temperature in more massive protostars, however, will eventually reach 10 megakelvins, at which point hydrogen begins to fuse by way of the proton-proton chain reaction to deuterium and then to helium. The onset of nuclear fusion leads over a relatively short time to a hydrostatic equilibrium in which energy released by the core prevents further gravitational collapse. The star thus evolves rapidly to a stable state.
New stars come in a variety of sizes and colors. They range in spectral type from hot and blue to cool and red, and in mass from less than 0.5 to more than 20 solar masses. The brightness and color of a star depend on its surface temperature, which in turn depends on its mass.
A new star will fall at a specific point on the main sequence of the Hertzsprung-Russell diagram. Small, cool red dwarfs burn hydrogen slowly and may remain on the main sequence for hundreds of billions of years, while massive hot supergiants will leave the main sequence after just a few million years. A mid-sized star like the Sun will remain on the main sequence for about 10 billion years. The Sun is thought to be in the middle of its lifespan; thus, it is on the main sequence. Once a star expends most of the hydrogen in its core, it moves off the main sequence.
MaturityAfter millions to billions of years, depending on its initial mass, the continuous fusion of hydrogen into helium will cause a build-up of helium in the core.
The later years and death of stars:
Low-mass star Some stars may fuse helium in core hot-spots, causing an unstable and uneven reaction as well as a heavy solar wind. In this case, the star will form no planetary nebula but simply evaporate, leaving little more than a brown dwarf. But a star of less than about 0.5 solar mass will never be able to fuse helium even after the core ceases hydrogen fusion. There simply is not a stellar envelope massive enough to bear down enough pressure on the core. These are the red dwarfs, such as Proxima Centauri, some of which will live thousands of times longer than the Sun. Recent astrophysical models suggest that red dwarfs of 0.1 solar masses may stay on the main sequence for almost six trillion years, and take several hundred billion more to slowly collapse into a white dwarf. (S&T, 22)
Mid-sized stars Once a medium-size star (between 0.4 and 3.4 solar masses) has reached the red giant phase, its outer layers continue to expand, the core contracts inward, and helium begins to fuse into carbon. In stars of less than 1.4 solar masses, the helium fusion process begins with an explosive burst of energy generation known as a helium flash.
Helium burning reactions are extremely sensitive to temperature, which causes great instability. Huge pulsations build up, which eventually give the outer layers of the star enough kinetic energy to be ejected as a planetary nebula. At the center of the nebula remains the core of the star, which cools down to become a small but dense white dwarf, typically weighing about 0.6 solar masses, but only the volume of the Earth.
White dwarfs Main article: white dwarfs White dwarfs are stable because the inward pull of gravity is balanced by the degeneracy pressure of the star's electrons. (This is a consequence of the Pauli exclusion principle.) With no fuel left to burn, the star radiates its remaining heat into space for thousands of millions of years. In the end, all that remains is a cold dark mass sometimes called a black dwarf. However, the universe is not old enough for any black dwarf stars to exist.
Supermassive stars After the outer layers of a star greater than five solar masses have swollen into a gigantic red supergiant, the core begins to yield to gravity and starts to shrink. As it shrinks, it grows hotter and denser, and a new series of nuclear reactions begin to occur. These reactions fuse progressively heavier elements, temporarily halting the collapse of the core.
It is known that in some supernovae, the intense gravity inside the supergiant forces the electrons into the atomic nuclei, where they combine with the protons to form neutrons. The electromagnetic forces keeping separate nuclei apart are gone (proportionally, if nuclei were the size of dust motes, atoms would be as large as football stadiums), and the entire core of the star becomes nothing but a dense ball of contiguous neutrons or a single atomic nucleus.
Black holes Main article: black holes It is widely believed that not all supernovae form neutron stars. If the stellar mass is high enough, the neutrons themselves will be crushed and the star will collapse until its radius is smaller than the Schwarzschild radius. The star has then become a black hole.
Geophysics is the study of the Earth by quantitative physical methods, especially by seismic, electromagnetic, and radioactivity methods, therefore Planetary Geophysics is the study of the planets by quantitative physical methods, especially by seismic, electromagnetic, and radioactivity methods. It includes the branches of: Seismology (earthquakes and elastic waves), planetary gravity, geodesy,Tectonophysics (geological processes in the planets), Mineral Physics and others. Geophysics can be both a part of physics and a part of Geology.
Geodesy of The Solar System, also called geodetics of the solar system, is the scientific discipline that deals with the measurement and representation of the planets of the Solar System, their gravitational fields and geodynamic phenomena (polar motion in three-dimensional, time-varying space. The science of geodesy has elements of both astrophysics and planetary sciences. The shape of the Earth is to a large extent the result of its rotation, which causes its equatorial bulge, and the competition of geologic processes such as the collision of plates and of vulcanism, resisted by the Earth's gravity field. These principles can be applied to the solid surface of Earth (orogeny; Few mountains are higher than 10 km, few deep sea trenches deeper than that because quite simply, a mountain as tall as, for example, 15 km, would develop so much pressure at its base, due to gravity, that the rock there would become plastic, and the mountain would slump back to a height of roughly 10 km in a geologically insignificant time. Some or all of these geologic principles can be applied to other planets besides Earth. For instance on Mars, whose surface gravity is much less, the largest volcano, Olympus Mons, is 27 km high at its peak, a height that could not be maintained on Earth. The Earth geoid is essentially the figure of the Earth abstracted from its topographic features. Therefore the Mars geoid is essentially the figure of Mars abstracted from its topographic features. Surveying and mapping are two important fields of application of geodesy.
Physics is the underlying physical science of any planet, yet many aspects of planets are not best described through their physics. Planetary science is the general term for ALL physical sciences that can be applied to planets in the Universe or else to a particular planet. Planetary science of the Earth is the overall physical science containing all the physical sciences related directly to our Earth. Planetary Science can be broadly divided into several major sciences: Geology, Oceanography and Atmospheres.
Geology of Solar System Planets contains Geology of Mercury, Geology of Venus, Geology of the Moon, Geology of Mars, Geology of Jupiter,Geology of Saturn, Geology of Uranus Geology of Neptune, Geology of Pluto
Geology of Other Planets Planetary geology (sometimes known as Astrogeology) refers to the application of geologic principles to other bodies of the solar system. However, specialised terms such as selenology (studies of the Moon), areology (of Mars), etc., are also in use. Most of the geological sciences related to the Earth can be directly applied to the study of non-Earth planets: Geology Fields or related disciplines Structural geology, Geomorphology., Economic geology, Mining geology, Geodetics, Geomorphology, Geophysics, Historical geology, Hydrogeology or geohydrology, Mineralogy, Paleoclimatology, Sedimentology, Seismology, Stratigraphy, Structural geology, Volcanology,Hydrology. Geothermometry (heating of the earth, heat flow, volcanology, and hot springs), Hydrology (ground and surface water, sometimes including glaciology).
Extrasolar Geology is currently a young science because only recently have extrasolar planets been found.
Atmospheres of Solar System Planets refers to the application of meteorological principles to other bodies of the solar system including the application of: Atmospheric electricity and terrestrial magnetism (including ionosphere, Van Allen belts, telluric currents, Radiant energy, etc.), Meteorology and Climatology. Aeronomy the study of the physical structure and chemistry of the atmosphere. Atmosphere of Planets of The Solar System includes http://www.astronomy.org/astronomy-survival/outer.html Mars Atmosphere includes Mars Atmosphere, Venus Atmosphere. Jupiter Atmosphere  Jupiter AtmosphereGreat Red Spot Great Red Spot http://www2.jpl.nasa.gov/galileo/mess44/promysso.html, Atmosphere on Jupiters-Moons, Atmosphere on Saturn http://www.nasm.si.edu/ceps/rpif/saturn/saturn.html http://www.physics.purdue.edu/astr263l/SStour/saturn.html http://www.abc.net.au/science/news/stories/s872839.htm. Atmosphere on Urnaus http://www.physics.purdue.edu/astr263l/SStour/uranus.html
Atmospheres of Extrasolar Planets is currently a young science because only recently have extrasolar planets been found. Astronomers are currently theorizing that the recently discovered extrasolar Jupiter-sized planets have continuous surface winds of many thousands of miles per hour caused by their highly elliptical orbit which brings them close to their parent star.
Earth telescopes can resolve some surface features of the nearby planets and so far, no life can be seen through the telescopes. However, Earth telescopes cannot resolve the surface features of any planet outside the solar system, so the search for life on other planets continues. While no incontestable evidence has been found for life outside of Earth, the scientific study of the theoretical basis for life on other bodies is progressing. Some scientists are trying to theorize which kinds of stars would have planets that hold life. Because life has overall fragile parameters for survival the general consensus is that only older stars would have planets circling them with life. From this they theorize which sections of our Milky Way Galaxy would most likely hold life. Other scientists theorize the quantity of civilizations that might exist in a galaxy and others are actually listening for the possible radio chatter of extraterrestrial technical civilizations. These sub-sciences of exobilogy can be categorized as follows:
Astrobiochemistry Exogenesis Most scientists hold that if extraterrestrial life exists, its evolution would have occurred independently in different places in the universe. An alternative hypothesis, held by a minority, is panspermia, which suggests that life in the universe could have stemmed from a smaller number of points of origin, and then spread across the universe, from habitable planet to habitable planet. These two hypotheses are not mutually exclusive. Alternative biochemistry includes Alternative Carbon Biochemistry where water is not the Solvent of Carbon Chains: Life forms based in ammonia rather than water are also considered, though this solution appears less optimal than water. Also included is Alternative Non-Carbon Biochemistry: Non-carbon based chemistry Silicon is usually considered the most likely alternative to carbon, though this remains improbable. Silicon life forms are proposed to have a crystalline morphology, and are theorized to be able to exist in high temperatures, such as planets closer to the sun.
Astrobiosphere is the entire area of a planet that supports life and includes Biosphere, Theory of Biosphere, Planetary Habitability Extrasolar planets Astronomers also search for extrasolar planets that would be conducive to life, especially those like OGLE-2005-BLG-390Lb which have been found to have Earth-like qualities.
Plants On Other Planets includes Extremophiles, Theoretical Astrobotany, Life On Jupiter, Life on Mars scientific theory, Independently in 1996 structures resembling bacteria were reportedly discovered in a meteorite, ALH84001, thought to be formed of rock ejected from Mars. This report is also controversial and scientific debate continues. (See Viking biological experiments.)
Humanoids-On-Other-Planets includes Humanoids-On-Other-Planets Origins- Speculations And Scientific Theory Panspermia. Extraterrestrial life along with the biochemical basis of extraterrestrial life, there remains a broader consideration of evolution and morphology.
Humanoids-On-Other-Planets Technical Civilizations includes Humanoids-On-Other-Planets Technical-Civilizations, Speculation And Theory.
Humanoids-On-Other-Planets Technical-Civilizations, Migrations Most scientists hold that if extraterrestrial life exists, its evolution would have occurred independently in different places in the universe. An alternative hypothesis, held by a minority, is panspermia, which suggests that life in the universe could have stemmed from a smaller number of points of origin, and then spread across the universe, from habitable planet to habitable planet.
Humanoids-On-Other-Planets Technical-Civilizations, Quantity of Drake Equation
Humanoids-On-Other-Planets-Civilizations On Local Stars includes Search For Humanoids-On-Other-Planets-Civilizations On Local-Stars, SETI
Astronomy is exploration of space through instruments based on Earth. Space Exploration through space travel is exploration of space by travel through it, either in person or by drone. Closely associated with Space travel is Space Station, either manned or unmanned. All man-made satellites are a form of unmanned or manned space stations.
There are Astronomical satellites, Biosatellites, Communications satellites, Miniaturized satellites, Navigation satellites, Reconnaissance satellites, Earth observation satellites, Earth observation satellites and others. There are many different kinds of orbits possible for these devices.
Further information can be found at Library of Congress Classifications TL787-4050 Astronautics, TL780-785.8 Rocket propulsion, TL787-4050 Space travel.
Space colonization is a colossal science that includes all of the scientific disciplines needed to be able to build colonies on non-Earth planets and planetoids.
Space Colonization Justification includes the sciences of Space and survival.
Space Colony Research And Development Man can practice living on other worlds by building permanently inhabitable cities in extremely hostile environments of the Earth: The poles and the deserts. This is discussed in the articles Biosphere 2 and BIOS-3. Currently manned Earth hostile-environment stations include Amundsen-Scott South Pole Station, Devon Island, Mars Arctic Research Station, Mars Desert Research Station, climate, underwater structures for planets with oceans or very heavy atmospheres and others.
Space Colony Location is the science of figuring out the best planets and the best locations on those planets for colonization. Because water is such a necessity for human survival most searches are for locations close to some kind of water. These issues and other related issues are discussed in the articles Colonization of Mars, Mars Society, Colonization of Mercury, Colonization of Venus, Venusian terraforming, Colonization of the Moon, Artemis Project, Europa, Phobos, Colonization of the asteroids and others.
Space Colonization Habitat science includes Space habitat, Human adaptation to space, Manmade closed ecological system, Planetary habitability, Domed city, Ocean colonization, Underground city and other sub-sciences. Further reading is available at Space Industrialization Dewy 629.44.
Space Colonization Health (Space Medicine Dewey 616.9)
Space Colonization Food Processing includes Space food and others.
Space Colonization Housing includes International Space Station.
Space Colonization Clothing includes Space suits
Space Colonization Construction includes Orbital Megastructures, station-keeping, Amundsen-Scott South Pole Station, Devon Island, Mars Arctic Research Station, Mars Desert Research Station, climate, underwater structures for planets with oceans or very heavy atmospheres and others.
Space Colonization Transportation includes Lunar rover
Space Colonization Materials includes Recycling
Space Colonization Energy includes Renewable energy
Space Colonization General Manufacturing includes Space Manufacturing
Space Colonization Operations includes space agencies, Space advocacy, Colonize the Cosmos, Artemis Project , National Space Society, Planetary Society, robotic exploration , search for extraterrestrial life, Space Settlement Institute, Students for the Exploration and Development of Space, NASA, ESA, Project Constellation
'Space Colonization Law and Protection includes Space Law
Space Defense is the science of defending the Earth from natural or unnatural threats from Space. Natural threats include Near Earth Asteroids and similar. Other issues are discussed in Missile Defense Command, United States Army Space and Missile Defense Command, Department of Defense Manned Space Flight Support Office, European Aeronautic Defense & Space and Joint Defense Space Research Facility.
Further information can be found at Library of Congress Classifications UG1500-1530 Military astronautics, 0UG1500-1530 space warfare, (Dewey 358).