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Space science is an all-encompassing term that describes most 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. Image File history File links Broom_icon. ... The Universe is defined as the summation of all particles and energy that exist and the space-time in which all events occur. ... A giant Hubble mosaic of the Crab Nebula, a supernova remnant Astronomy (also frequently referred to as astrophysics) is the scientific study of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earths atmosphere (such as the cosmic background radiation). ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ...

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. The Library of Congress is the de facto national library of the United States and the research arm of the United States Congress. ... The Dewey Decimal Classification (DDC, also called the Dewey Decimal System) is a system of library classification developed by Melvil Dewey (1851–1931) in 1876, and since greatly modified and expanded in the course of the twenty-two major revisions which have occurred up until 2004. ...

Astronomy

Astronomical Methods

Palomar Telescope.

Main article: Astronomy

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. The 200 inch telescope on Mount Palomar. ... The 200 inch telescope on Mount Palomar. ... A giant Hubble mosaic of the Crab Nebula, a supernova remnant Astronomy (also frequently referred to as astrophysics) is the scientific study of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earths atmosphere (such as the cosmic background radiation). ...

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. The Very Large Array, a radio interferometer in New Mexico, USA Radio astronomy is a subfield of astronomy that studies celestial objects in the radio frequency portion of the electromagnetic spectrum. ... The 64 meter radio telescope at Parkes Observatory A radio telescope is a form of directional radio antenna most often used in radio astronomy and in tracking and collecting data from satellites and space probes (see Deep Space Network), and are also used in the SETI project. ... In cosmology, the cosmic microwave background radiation (most often abbreviated CMB but occasionally CMBR, CBR or MBR, also referred as relic radiation) is a form of electromagnetic radiation discovered in 1965 that fills the entire universe. ... According to the Big Bang model, the universe emerged from an extremely dense and hot state. ... It has been suggested that Radio pulsar be merged into this article or section. ... Optical astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light. ... ROSAT image of X-ray fluorescence of, and occultation of the X-ray background by, the Moon. ... The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. ... Gamma-ray astronomy is the astronomical study of gamma rays. ... Illustration of CGRO The Compton Gamma Ray Observatory(CGRO) was the second of the NASA Great Observatories to be launched to space, following the Hubble Space Telescope. ... Neutrino astronomy is the science of observing astronomical phenomena by detecting neutrinos, a product of thermonuclear reactions going on inside every star. ... For the concept in fluid dynamics and meteorology, see Gravity wave. ...

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. A space observatory is any object in outer space which is used for observation of distant planets, galaxies, and other outer space objects. ... The Hubble Space Telescope (HST) is a telescope in orbit around the Earth, named after astronomer Edwin Hubble. ... The Rossi X-ray Timing Explorer (RXTE) satellite observes the fast-moving, high-energy worlds of black holes, neutron stars, X-ray pulsars and bursts of X-rays that light up the sky and then disappear forever. ... A millisecond pulsar (MSP), often referred to as recycled pulsar, is a pulsar with a rotational period in the range of about 1-10 milliseconds. ... It has been suggested that this article or section be merged into Pulsar. ...

Spectroscopy Extremely high resolution spectrogram of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of the interaction between radiation (electromagnetic radiation, or light, as well as particle radiation) and matter. ...

Astronomy teaching tools include Planetariums and others. // A planetarium is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation. ...

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

Descriptive 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 photograhic 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 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. Superclusters are large groupings of smaller galaxy groups and clusters, and are among the largest structures of the cosmos. ... Elliptical Galaxy M49 (also known as Messier Object 49, Messier 49, M49, or NGC 4472) is an elliptical galaxy in the Virgo constellation. ... The Whirlpool Galaxy (also known as Messier 51, M51, or NGC 5194) is an interacting[3] grand-design[4] spiral galaxy located at a distance of approximately 23 million light-years in the constellation Canes Venatici. ... Spiral Galaxy M58 (also known as Messier Object 58, Messier 58, M58, or NGC 4579) is a spiral galaxy in the Virgo constellation. ... M59, courtesy of NOAO. Elliptical Galaxy M59 (also known as Messier Object 59, Messier 59, M59, or NGC 4621) is an elliptical galaxy in the constellation Virgo. ... Elliptical Galaxy M60 (also known as Messier Object 60, Messier 60, M60, or NGC 4649) is an elliptical galaxy in the Virgo constellation. ... M61, courtesy of NOAO Spiral Galaxy M61 (also known as Messier Object 61 or NGC 4303) is a large spiral galaxy of type SABbc in the Virgo Cluster. ... The Sunflower Galaxy (also known as Spiral Galaxy M63, Messier Object 63, Messier 63, M63, or NGC 5055) is a spiral galaxy in the Canes Venatici constellation. ... The Black Eye Galaxy (aka Messier 64, M64, or NGC 4826) was discovered by Edward Pigott in March 1779, and independently by Johann Elert Bode in April of the same year, as well as by Charles Messier in 1780. ... Spiral Galaxy M65 (also known as Messier Object 65, Messier 65, M65, or NGC 3623) is a spiral galaxy in the Leo constellation. ... Messier 66 (also known as NGC 3627) is an intermediate spiral galaxy about 36 million light-years away in the constellation Leo. ...

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. M31 in a small telescope The Andromeda Galaxy (IPA: , also known as Messier 31, M31, or NGC 224; older texts often called it the Andromeda Nebula) is a spiral galaxy approximately 2. ... Elliptical Galaxy M32 (also known as Messier Object 32, Messier 32, M32, or NGC 221) is a dwarf elliptical galaxy in the Andromeda constellation, a satellite of the Andromeda Galaxy, and a member of the Local Group galaxies. ... The Triangulum Galaxy (also known as Messier 33 or NGC 598) is a spiral galaxy about 3. ...

Image of the Orion and neighbouring arms

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 approximately 12 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. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... The Crab Nebula (catalogue designations M 1, NGC 1952, Taurus A) is a supernova remnant in the constellation of Taurus. ... Planetary Nebula M57 (also known as the Ring Nebula, NGC 6720 or Messier Object 57) is located in the constellation Lyra. ...

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 The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated south of Orions Belt. ... Open Cluster M39 (also known as Messier Object 39, Messier 39, M39, or NGC 7092) is an open cluster in the Cygnus constellation. ... The Beehive Cluster (also known as The Beehive, Praesepe, Open Cluster M44, Messier Object 44, Messier 44, M44, or NGC 2632) is an open cluster in the constellation Cancer. ... A shorter exposure shows less nebulosity. ... This list of the nearest stars to Earth is ordered by increasing distance out to a maximum of 5 parsecs (16. ...

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".

Solar system includes Scientific Study of Solar System Planets, Venus, Mercury, Saturn, Jupiter, Uranus, Neptune, Mars, and Moon Major features of the Solar System (not to scale; from left to right): Pluto, Neptune, Uranus, Saturn, Jupiter, the asteroid belt, the Sun, Mercury, Venus, Earth and its Moon, and Mars. ... Adjectives: Venusian or (rarely) Cytherean Atmosphere Surface pressure: 9. ... This article is about the planet. ... Adjectives: Saturnian Atmosphere Surface pressure: 140 kPa Composition: >93% hydrogen >5% helium 0. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% Molecular hydrogen ~13% Helium 0. ... Adjectives: Uranian Atmosphere Surface pressure: 120 kPa (at the cloud level) Composition: 83% Hydrogen 15% Helium 1. ... Note: This article contains special characters. ... Adjectives: Martian Atmosphere Surface pressure: 0. ... Apparent magnitude: up to -12. ...

Further reading can be found in the Library of Congress Classification QB495-903 Descriptive astronomy (Dewey 523)

Physics Of The Universe / Astrophysics

Timeline of Origin of Space.

Main article: Astrophysics

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: Image File history File links Size of this preview: 800 × 576 pixelsFull resolution (3000 × 2159 pixel, file size: 1. ... Image File history File links Size of this preview: 800 × 576 pixelsFull resolution (3000 × 2159 pixel, file size: 1. ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ...

Astrophysical Theory includes general relativity and others. An illustration of a rotating black hole at the center of a galaxy General relativity (GR) (aka general theory of relativity (GTR)) is the geometrical theory of gravitation published by Albert Einstein in 1915/16. ...

Astrophysical Processes includes baryonic and others. Combinations of three u, d or s-quarks with a total spin of 3/2 form the so-called baryon decuplet. ...

Physical Processes, General includes Mechanics, Electromagnetism, electromagnetic forces, Statistical Mechanics, Thermodynamics, Quantum Mechanics, relativity, gravity and others. Mechanics (Greek ) is the branch of physics concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effect of the bodies on their environment. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... In physics, the electromagnetic force is the force that the electromagnetic field exerts on electrically charged particles. ... Statistical mechanics is the application of probability theory, which includes mathematical tools for dealing with large populations, to the field of mechanics, which is concerned with the motion of particles or objects when subjected to a force. ... Thermodynamics (from the Greek θερμη, therme, meaning heat and δυναμις, dunamis, meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ... Fig. ... Two-dimensional analogy of space-time curvature described in General Relativity. ... Gravity is a force of attraction that acts between bodies that have mass. ...

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. The Universe is defined as the summation of all particles and energy that exist and the space-time in which all events occur. ... According to the Big Bang theory, the universe originated in an infinitely dense and physically paradoxical singularity. ... WMAP image of the CMB anisotropy,Cosmic microwave background radiation(June 2003) The cosmic microwave background radiation (CMB) is a form of electromagnetic radiation that fills the whole of the universe. ... In astronomy, voids are the empty spaces between filaments, the largest-scale structures in the Universe that contain very few, or no, galaxies. ... Galaxy groups and clusters are super-structures in the spread of galaxies of the cosmos. ...

Astrophysical Plasma includes plasma and quasineutrality and others. A plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation. ... A plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation. ...

Cosmic Plasmas Between Stars, (Diffuse Plasmas) includes intergalactic space, intergalactic medium, interstellar medium, interplanetary medium, interstellar space, heliospheric current sheet, interplanetary medium, Solar wind and others. Intergalactic space is the physical space between galaxies. ... Intergalactic space is the physical space between galaxies. ... The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ... Heliospheric current sheet, the largest structure in the Solar System, results from the influence of the Suns rotating magnetic field on the plasma in the interplanetary medium (Solar Wind) [1]. (click to enlarge) The interplanetary medium is the material which fills the solar system and through which all the... Interstellar Space was one of the last albums recorded before the death of John Coltrane in 1967. ... Heliospheric current sheet The Heliospheric current sheet (HCS) is the surface within the Solar System where the polarity of the Suns magnetic field changes from north to south. ... Heliospheric current sheet, the largest structure in the Solar System, results from the influence of the Suns rotating magnetic field on the plasma in the interplanetary medium (Solar Wind) [1]. (click to enlarge) The interplanetary medium is the material which fills the solar system and through which all the... The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ...

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. STARS can mean: Shock Trauma Air Rescue Society Special Tactics And Rescue Service, a fictional task force that appears in Capcoms Resident Evil video game franchise. ... A Plasma lamp In physics and chemistry, a plasma is an ionized gas, and is usually considered to be a distinct phase of matter. ... An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ... Internal view of the JET tokamak superimposed with an image of a plasma taken with a visible spectrum video camera. ... Magnetohydrodynamics (MHD) (magnetofluiddynamics or hydromagnetics) is the academic discipline which studies the dynamics of electrically conducting fluids. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... (help· info), (from the German bremsen, to brake and Strahlung, radiation, thus, braking radiation), is electromagnetic radiation produced by the acceleration of a charged particle, such as an electron, when deflected by another charged particle, such as an atomic nucleus. ... Physical cosmology, as a branch of astrophysics, is the study of the large-scale structure of the universe and is concerned with fundamental questions about its formation and evolution. ... In Big Bang cosmology, reionization is the process that reionized the matter in the universe after the dark ages. It is the second of two major phase changes of hydrogen gas in the universe. ... Ambipolar diffusion is diffusion of positive and negative particles in a plasma at the same rate due to their interaction via the electric field. ... Thousands of particles explode from the collision point of two relativistic (100 GeV per ion) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ...

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)

Cosmology

Galaxies in the Hubble Deep Field.

Main article: Galaxy

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. Image File history File links Size of this preview: 584 × 600 pixelsFull resolution (779 × 800 pixel, file size: 143 KB, MIME type: image/jpeg) Hubble Deep Field (full mosaic) released by NASA on January 15, 1996. ... Image File history File links Size of this preview: 584 × 600 pixelsFull resolution (779 × 800 pixel, file size: 143 KB, MIME type: image/jpeg) Hubble Deep Field (full mosaic) released by NASA on January 15, 1996. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ...

Galaxy Formation and Evolution includes Galaxies, elliptical galaxies Giant Galaxies, Spiral Galaxies, M31 The Andromeda Galaxy and others. NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ... An elliptical galaxy is a type of galaxy in the Hubble sequence characterized by the following physical properties: The giant elliptical galaxy NGC 4881 (the spherical glow at upper left) lies at the edge of the Coma Cluster of Galaxies. ... M31 in a small telescope The Andromeda Galaxy (IPA: , also known as Messier 31, M31, or NGC 224; older texts often called it the Andromeda Nebula) is a spiral galaxy approximately 2. ... M31 in a small telescope The Andromeda Galaxy (IPA: , also known as Messier 31, M31, or NGC 224; older texts often called it the Andromeda Nebula) is a spiral galaxy approximately 2. ...

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. Simulated view of a black hole in front of the Milky Way. ... The Globular Cluster M80 in the constellation Scorpius is located about 28,000 light years from the Sun and contains hundreds of thousands of stars. ... An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ... Prograde motion is the motion of a planetary body in a direction similar to that of other bodies within its system, and is sometimes called direct motion, especially in astrology. ... STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... Interstellar cloud is the generic name given to an accumulation of gas, plasma and dust in our and other galaxies. ... Monoceros Ring is a proposed ring of stars around the Milky Way which consists of stars torn from the Canis Major Dwarf Galaxy as it merges with the Milky Way over the course of billions of years. ... “Gravity” redirects here. ... This gyroscope remains upright while spinning due to its angular momentum. ... The centripetal force is the external force required to make a body follow a circular path at constant speed. ... Comet Shoemaker-Levy 9 after breaking up under the influence of Jupiters tidal forces. ... Viscosity is a measure of the resistance of a fluid to deform under shear stress. ... Two bodies with a slight difference in mass orbiting around a common barycenter. ... An accretion disc (or accretion disk) is a structure formed by material falling into a gravitational source. ... An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. ... A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ... The image above shows the optical afterglow of gamma ray burst GRB-990123 taken on January 23, 1999. ...

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. STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... Interstellar cloud is the generic name given to an accumulation of gas, plasma and dust in our and other galaxies. ... Monoceros Ring is a proposed ring of stars around the Milky Way which consists of stars torn from the Canis Major Dwarf Galaxy as it merges with the Milky Way over the course of billions of years. ... “Gravity” redirects here. ... This gyroscope remains upright while spinning due to its angular momentum. ... The centripetal force is the external force required to make a body follow a circular path at constant speed. ... Comet Shoemaker-Levy 9 after breaking up under the influence of Jupiters tidal forces. ... Viscosity is a measure of the resistance of a fluid to deform under shear stress. ... Two bodies with a slight difference in mass orbiting around a common barycenter. ... For the science fiction film, see Event Horizon (film). ... Simulated view of a black hole in front of the Milky Way. ...

Stellar science

Quintuplet Cluster- Very young and near the Galactic Center.

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. Image File history File links Size of this preview: 594 × 600 pixelsFull resolution (999 × 1009 pixel, file size: 1. ... Image File history File links Size of this preview: 594 × 600 pixelsFull resolution (999 × 1009 pixel, file size: 1. ... “Sol” redirects here. ...

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 dynamics is the branch of astrophysics which describes in a statistical way the collective motions of stars subject to their mutual gravity. ... STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... In astronomy, stellar evolution is the sequence of radical changes that a star undergoes during its lifetime (the time in which it emits light and heat). ... For the science fiction film, see Event Horizon (film). ... Simulated view of a black hole in front of the Milky Way. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... A giant Hubble mosaic of the Crab Nebula, a supernova remnant Astronomy (also frequently referred to as astrophysics) is the scientific study of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earths atmosphere (such as the cosmic background radiation). ... STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ...

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. Observation is an activity of a sapient or sentient living being (e. ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ... The simplest commonly used model of stellar structure is the spherically symmetric quasi-static model, which assumes that a star is very close to an equilibrium state, and that it is spherically symmetric. ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ...

Birth of stars is discussed in Main article: Star Formation Media:Example. ...

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. Dark Nebula Dark Nebula (Dark Zero in the original Japanese version) is a fictional character in the Kirby series of video games for Nintendo. ... A stellar nursery is a massive cosmic dust cloud in which microscopic particles may slowly aggregate due to gravitational attraction and eventually give rise to protostars and subsequently planetary systems, with one or more stars and planets. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ... “Sol” redirects here. ... A light-year, symbol ly, is the distance light travels in one year: exactly 9. ...

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 (M_J) 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. The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ... This brown dwarf (smaller object) orbits the star Gliese 229, which is located in the constellation Lepus about 19 light years from Earth. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% Molecular hydrogen ~13% Helium 0. ... Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6500 of hydrogen (~154 PPM). ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Overveiw of the proton-proton chain. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Standard atomic weight 4. ... Hydrostatic equilibrium occurs when compression due to gravity is balanced by a pressure gradient which creates a pressure gradient force in the opposite direction. ...

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. In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ...

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. Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ... The Hertzsprung-Russell diagram (usually referred to by the abbreviation H-R diagram or HRD, also known as a Colour-Magnitude diagram, or CMD) shows the relationship between absolute magnitude, luminosity, classification, and effective temperature of stars. ... -1... Supergiants are the most massive stars. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...

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) The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ... NGC 6543, the Cats Eye Nebula A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by certain types of stars at the end of their lives. ... This brown dwarf (smaller object) orbits the star Gliese 229, which is located in the constellation Lepus about 19 light years from Earth. ... -1... The red dwarf star Proxima Centauri, part of the Alpha Centauri star system, is the nearest star to the Sun at a distance of 4. ... This article or section does not adequately cite its references or sources. ...

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.^[1] According to the Hertzsprung-Russell diagram, a red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giant stars. ... A Helium flash is the sudden beginning of helium burning in the core of intermediate mass stars, or on the surface of an accreting white dwarf star. ...

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. The kinetic energy of an object is the extra energy which it possesses due to its motion. ... NGC 6543, the Cats Eye Nebula A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by certain types of stars at the end of their lives. ... This article or section does not adequately cite its references or sources. ...

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. This article or section does not adequately cite its references or sources. ... Degenerate matter is matter which has sufficiently high density that the dominant contribution to its pressure arises from the Pauli exclusion principle. ... The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925. ... A black dwarf is a hypothetical astronomical object: a white dwarf so old that it has cooled down so that it no longer emits significant heat or light. ...

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. Supergiants are the most massive stars. ...

Neutron stars Main article: neutron star 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. A neutron star is one of the few possible endpoints of stellar evolution. ... e- redirects here. ... In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... This article or section does not adequately cite its references or sources. ...

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. Simulated view of a black hole in front of the Milky Way. ... The Schwarzschild radius (sometimes inappropriately referred to as the gravitational radius[1]) is a characteristic radius associated with every mass. ...

Non-Earth Planetary Science

Solar System Planets.

Planetary Processes, General includes Planetary science, Planets, Comets, Asteroids and others. Image File history File links Download high resolution version (1024x1274, 113 KB) Original caption released with image This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars... Image File history File links Download high resolution version (1024x1274, 113 KB) Original caption released with image This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars... Planetary science, also known as planetology or planetary astronomy, is the science of planets, or planetary systems, and the solar system. ... A planet (from the Greek πλανήτης, planetes or wanderers) is a body of considerable mass that orbits a star and that produces very little or no energy through nuclear fusion. ... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small astronomical object similar to an asteroid but composed largely of ice. ... 253 Mathilde, a C-type asteroid. ...

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. This article is about Earth as a planet. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Seismic reflection data Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earths subsurface from reflected seismic waves. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... A planet (from the Greek πλανήτης, planetes or wanderers) is a body of considerable mass that orbits a star and that produces very little or no energy through nuclear fusion. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Seismic reflection data Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earths subsurface from reflected seismic waves. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... Radioactivity may mean: Look up radioactivity in Wiktionary, the free dictionary. ... Seismology (from the Greek seismos = earthquake and logos = word) is the scientific study of earthquakes and the propagation of elastic waves through the Earth. ... An earthquake is the result from the sudden release of stored energy in the Earths crust that creates seismic waves. ... A wave is a disturbance that propagates through space or spacetime, transferring energy and momentum and sometimes angular momentum. ... It has been suggested that geodetic system be merged into this article or section. ... Tectonophysics, a branch of geophysics, is the study of rock deformation and of dynamic geophysical processes. ...

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. “Gravity” redirects here. ... This article needs to be wikified. ... For other uses, see Volcano (disambiguation). ... Gravity is a force of attraction that acts between bodies that have mass. ... // Orogeny (Greek for mountain generating) is the process of mountain building, and may be studied as a tectonic structural event, as a geographical event and a chronological event, in that orogenic events cause distinctive structural phenomena and related tectonic activity, affect certain regions of rocks and crust and happen within... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin in Canberra, Australia. ... This article or section does not cite any references or sources. ... Olympus Mons (Latin, Mount Olympus) is the tallest known volcano and mountain in our solar system, located on the planet Mars at approximately . ... The GOCE project will measure high-accuracy gravity gradients and provide an accurate geoid model based on the Earths gravity field. ... Surveyor at work with a leveling instrument. ... The word mapping has several senses: In mathematics and related technical fields, it is some kind of function: see map (mathematics). ...

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 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). Astrogeology is the scientific discipline concerned with the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites. ... Apparent magnitude: up to -12. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Structural geology is the study of the three dimensional distribution of rock bodies and their planar or folded surfaces, and their internal fabrics. ... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... Economic geology is concerned with earth materials that can be utilized for economic and/or industrial purposes. ... Chuquicamata, the largest open pit copper mine in the world, Chile. ... This article or section should include material from Erdmessung. ... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... ‹ The template below has been proposed for deletion. ... Historical geology is the use of the principles of geology to reconstruct and understand the history of the Earth. ... Hydrogeology (hydro- meaning water, and -geology meaning the study of the Earth) is the part of hydrology that deals with the distribution and movement of groundwater in the soil and rocks of the Earths crust, (commonly in aquifers). ... Hydrogeology (hydro- meaning water, and -geology meaning the study of rocks) is the part of hydrology that deals with the distribution and movement of groundwater in the soil and rocks of the Earths crust (commonly in Aquifers). ... Mineralogy is an earth science that involves the chemistry, crystal structure, and physical (including optical) properties of minerals. ... Paleoclimatology is the study of climate change taken on the scale of the entire history of the Earth. ... Sedimentology is the branch of geology primarily concerned with understanding the characteristics of sediments, sedimentary processes and sedimentary rocks originally deposited in sedimentary basins. ... Seismology (from the Greek seismos = earthquake and logos = word) is the scientific study of earthquakes and the propagation of elastic waves through the Earth. ... This article does not cite any references or sources. ... Structural geology is the study of the three dimensional distribution of rock bodies and their planar or folded surfaces, and their internal fabrics. ... Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma, and related geological phenomena. ... For other uses, see Volcano (disambiguation). ... Water covers 70% of the Earths surface. ... Lateral moraine on a glacier joining the Gorner Glacier, Zermatt, Switzerland. ...

Regional planetary geology 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 Of all the terrestrial planets in the Solar System, the geology of Mercury is the least understood. ... A global view of Venus made from a mosaic of radar images from the Magellan spacecraft, centred at 90 degrees longitude. ... Exploring Shorty crater during the Apollo 17 mission to the Moon. ... The geology of Mars, also known as areology (after Ares), refers to the study of the composition, structure, physical properties, history and the processes that shape the planet Mars. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% Molecular hydrogen ~13% Helium 0. ... Adjectives: Saturnian Atmosphere Surface pressure: 140 kPa Composition: >93% hydrogen >5% helium 0. ... Adjectives: Uranian Atmosphere Surface pressure: 120 kPa (at the cloud level) Composition: 83% Hydrogen 15% Helium 1. ... Note: This article contains special characters. ... Adjectives: Plutonian Atmosphere Surface pressure: 0. ...

Atmosphere of Other Planets / Extrasolar Atmosphere 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 [1] 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 Cloud to ground Lightning in the global atmospheric electrical circuit. ... The magnetosphere shields the surface of the Earth from the charged particles of the solar wind. ... Relationship of the atmosphere and ionosphere The ionosphere is the uppermost part of the atmosphere, distinguished because it is ionized by solar radiation. ... Van Allen radiation belts The Van Allen Radiation Belt is a torus of energetic charged particles (plasma) around Earth, held in place by Earths magnetic field. ... A telluric current is an electric current in the Earth (both land and sea). ... Radiant energy is the energy of electromagnetic waves. ... Satellite image of Hurricane Hugo with a polar low visible at the top of the image. ... Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time,[1] and is a branch of the atmospheric sciences. ... Atmospheric sciences is an umbrella term for the study of the atmosphere, its processes, the effects other systems have on the atmosphere, and the effects of the atmosphere on these other systems. ... Mars, the fourth planet from the Sun, has a very different atmosphere from that of Earth. ... Adjectives: Venusian or (rarely) Cytherean Atmosphere Surface pressure: 9. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% Molecular hydrogen ~13% Helium 0. ... Adjectives: Jovian Atmosphere Surface pressure: 20–200 kPa[4] (cloud layer) Composition: ~86% Molecular hydrogen ~13% Helium 0. ...

Exobiology / Extraterrestrial Life

Silicon Based Life

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: Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...

Habitable Zone Astrobiology is discussed in Galactic Habitable Zone and Solar System Habitable Zone. In astronomy a habitable zone (HZ) is a region of space where conditions are favorable for the creation of life. ... It has been suggested that Goldilocks phenomenon be merged into this article or section. ...

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.^[2] 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. Exogenesis is an episode from the third season of the science-fiction television series Babylon 5. ... This article is about evolution in biology. ...