 Planets and dwarf planets of the Solar System; while the sizes are to scale, the relative distances from the Sun are not. The Solar System or solar system[a] consists of the Sun and the other celestial objects gravitationally bound to it: the eight planets, their 166 known moons,[1] three dwarf planets (Ceres, Pluto, and Eris and their four known moons), and billions of small bodies. This last category includes asteroids, Kuiper belt objects, comets, meteoroids, and interplanetary dust. An artists concept of a protoplanetary disc. ...
A star system or stellar system is a small number of stars that orbit each other,[1] bound by gravitational attraction. ...
An extrasolar planet, or exoplanet, is a planet beyond the Solar System. ...
Image File history File links Download high-resolution version (1280x720, 54 KB)The solar system is the largest known in the galaxy. ...
Image File history File links Download high-resolution version (1280x720, 54 KB)The solar system is the largest known in the galaxy. ...
Sol redirects here. ...
Astronomical objects are significant physical entities, associations or structures which current science has confirmed to exist in space. ...
Gravity redirects here. ...
This article is about the astronomical term. ...
A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ...
Artists impression of Pluto (background) and Charon (foreground). ...
Spectral type: G[8] Absolute magnitude: 3. ...
For other uses, see Pluto (disambiguation). ...
Absolute magnitude: −1. ...
A Small Solar System Body (SSSB) is a term defined in 2006 by the International Astronomical Union to describe objects in the Solar System that are neither planets nor dwarf planets: [1] This encompasses: all minor planets apart from the dwarf planets, : the classical asteroids, (except for 1 Ceres, the...
For other uses, see Asteroid (disambiguation). ...
The Kuiper belt, derived from data from the Minor Planet Center. ...
Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ...
“Meteor†redirects here. ...
Interplanetary dust cloud The interplanetary dust cloud has been studied for many years in order to understand its nature, origin, and relationship to solar systems (our own, as well as extrasolar systems). ...
In broad terms, the charted regions of the Solar System consist of the Sun, four terrestrial inner planets, an asteroid belt composed of small rocky bodies, four gas giant outer planets, and a second belt, the Kuiper belt, composed of icy objects. Beyond the Kuiper belt is the scattered disc, the heliopause, and ultimately the hypothetical Oort cloud. The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale. ...
For other uses, see Asteroid (disambiguation). ...
This article does not cite any references or sources. ...
The Kuiper belt, derived from data from the Minor Planet Center. ...
Eris, the largest known scattered disc object (center), and its moon Dysnomia (left of center). ...
The heliosphere is a bubble in space produced by the solar wind. ...
Artists rendering of the Oort cloud and the Kuiper Belt. ...
In order of their distances from the Sun, the terrestrial planets are:
The outer gas giants (or jovians) are: This article is about the planet. ...
For other uses, see Venus (disambiguation). ...
This article is about Earth as a planet. ...
Adjectives: Martian Atmosphere Surface pressure: 0. ...
The three dwarf planets are For other uses, see Jupiter (disambiguation). ...
This article is about the planet. ...
For other uses, see Uranus (disambiguation). ...
For other uses, see Neptune (disambiguation). ...
- Ceres, the largest object in the asteroid belt;
- Pluto, the largest known Kuiper belt object; and
- Eris, the largest of the three which lies in the scattered disc.
Six of the eight planets and two of the dwarf planets are in turn orbited by natural satellites, usually termed "moons" after Earth's Moon, and each of the outer planets is encircled by planetary rings of dust and other particles. All the planets except Earth are named after deities from Greco-Roman mythology. Spectral type: G[8] Absolute magnitude: 3. ...
For other uses, see Pluto (disambiguation). ...
Absolute magnitude: −1. ...
A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ...
This article is about Earths moon. ...
A planetary ring is a ring of dust and other small particles orbiting around a planet in a flat disc-shaped region. ...
The bust of Zeus found at Otricoli (Sala Rotonda, Museo Pio-Clementino, Vatican) Greek mythology is the body of stories belonging to the Ancient Greeks concerning their gods and heroes, the nature of the world and the origins and significance of their own cult and ritual practices. ...
A head of Minerva found in the ruins of the Roman baths in Bath Roman mythology, the mythological beliefs of the people of Ancient Rome, can be considered as having two parts. ...
For other uses, see Mythology (disambiguation). ...
Terminology  The zones of the Solar system: the inner solar system, the asteroid belt, the giant planets (jovians) and the Kuiper Belt. Orbits not to scale. - See also: Definition of planet
Objects orbiting the Sun are divided into three classes: planets, dwarf planets, and small Solar System bodies. Photograph of the planet Neptune and its moon Triton, taken by Voyager 2 as it entered the outer solar system. ...
Two bodies with a slight difference in mass orbiting around a common barycenter. ...
A planet is any body in orbit around the Sun that a) has enough mass to form itself into a spherical shape and b) has cleared its immediate neighbourhood of all smaller objects. By this definition, the Solar System has eight known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. From the time of its discovery in 1930 until 2006, Pluto was considered the Solar System's ninth planet. But in the late 20th and early 21st centuries, many objects similar to Pluto were discovered in the outer Solar System, most notably Eris, which is slightly larger than Pluto. On August 24, 2006, the International Astronomical Union defined the term "planet" for the first time, excluding Pluto and reclassifying it under the new category of dwarf planet along with Eris and Ceres.[2] A dwarf planet is not required to clear its neighbourhood of other celestial bodies. Other objects that may become classified as dwarf planets are Sedna, Orcus, and Quaoar. This article is about the astronomical term. ...
For other uses, see Mass (disambiguation). ...
For other uses, see Sphere (disambiguation). ...
This article or section may be confusing or unclear for some readers, and should be edited to rectify this. ...
is the 236th day of the year (237th in leap years) in the Gregorian calendar. ...
Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...
IAU redirects here. ...
The final definition left the solar system with eight planets. ...
Artists impression of Pluto (background) and Charon (foreground). ...
Absolute magnitude: −1. ...
Spectral type: G[8] Absolute magnitude: 3. ...
you are abunch of bull | bgcolour=#FFFFC0 | name=90377 Sedna | image= | caption= Sedna is located in the center of the green circle | discovery=yes | discoverer=M. Brown, C. Trujillo, D. Rabinowitz | discovered=November 14, 2003 | mp_name=90377 Sedna | alt_names= | mp_category=Trans-Neptunian object | epoch=September 26, 1990 (JD 2448160. ...
90482 Orcus (originally known by the provisional designation 2004 DW) is a Kuiper Belt object (KBO) that was discovered by Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University. ...
50000 Quaoar (pronounced kwaa·waar or kwow·ər, English IPA: , Tongva ) [2] is a Trans-Neptunian object orbiting the Sun in the Kuiper belt. ...
The remainder of the objects in orbit around the Sun are small Solar System bodies (SSSBs).[3] A Small Solar System Body (SSSB) is a term defined in 2006 by the International Astronomical Union to describe objects in the Solar System that are neither planets nor dwarf planets: [1] This encompasses: all minor planets apart from the dwarf planets, : the classical asteroids, (except for 1 Ceres, the...
Natural satellites, or moons, are those objects in orbit around planets, dwarf planets and SSSBs, rather than the Sun itself. A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ...
Astronomers usually measure distances within the Solar System in astronomical units (AU). One AU is the approximate distance between the Earth and the Sun, or roughly 149,598,000 km (93,000,000 mi). Pluto is roughly 38 AU from the Sun while Jupiter lies at roughly 5.2 AU. One light-year, the best known unit of interstellar distance, is roughly 63,240 AU. A body's distance from the Sun varies in the course of its year. Its closest approach to the Sun is called its perihelion, while its farthest distance from the Sun is called its aphelion. The astronomical unit (AU or au or a. ...
“km†redirects here. ...
“Miles†redirects here. ...
A light-year, symbol ly, is the distance light travels in one year: exactly 9. ...
A year (from Old English gēr) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ...
This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ...
This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ...
Informally, the Solar System is sometimes divided into separate zones. The inner Solar System includes the four terrestrial planets and the main asteroid belt. Some define the outer Solar System as comprising everything beyond the asteroids.[4] Others define it as the region beyond Neptune, with the four gas giants considered a separate "middle zone".[5] The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale. ...
This article does not cite any references or sources. ...
Layout and structure
 The ecliptic viewed in sunlight from behind the Moon in this Clementine image. From left to right: Mercury, Mars, Saturn. The principal component of the Solar System is the Sun, a main sequence G2 star that contains 99.86% of the system's known mass and dominates it gravitationally.[6] Jupiter and Saturn, the Sun's two largest orbiting bodies, account for more than 90% of the system's remaining mass.[b] Image File history File linksMetadata Solarsystem. ...
Image File history File linksMetadata Solarsystem. ...
Clementine was a joint space project between the Ballistic Missile Defense Organization (BMDO, previously the Strategic Defense Initiative Organization, or SDIO) and NASA. The objective of the mission was to test sensors and spacecraft components under extended exposure to the space environment and to make scientific observations of the Moon...
Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ...
In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ...
This article is about the astronomical object. ...
For other uses, see Mass (disambiguation). ...
Gravity redirects here. ...
Most large objects in orbit around the Sun lie near the plane of Earth's orbit, known as the ecliptic. The planets are very close to the ecliptic while comets and Kuiper belt objects are usually at significantly greater angles to it. The plane of the ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft. ...
Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ...
The Kuiper belt, derived from data from the Minor Planet Center. ...
 The orbits of the bodies in the Solar System to scale (clockwise from top left) All of the planets and most other objects also orbit with the Sun's rotation in a counter-clockwise direction as viewed from a point above the Sun's north pole. There are exceptions, such as Halley's Comet. This NASA diagram demonstrates the presumed distance of the Oort cloud compared to the solar systems planets, the Kuiper belt, and the 90377 Sedna planetoid. ...
This NASA diagram demonstrates the presumed distance of the Oort cloud compared to the solar systems planets, the Kuiper belt, and the 90377 Sedna planetoid. ...
This article is about the comet. ...
Objects travel around the Sun following Kepler's laws of planetary motion. Each object orbits along an approximate ellipse with the Sun at one focus of the ellipse. The closer an object is to the Sun, the faster it moves. The orbits of the planets are nearly circular, but many comets, asteroids and objects of the Kuiper belt follow highly-elliptical orbits. Johannes Keplers primary contributions to astronomy/astrophysics were his three laws of planetary motion. ...
To cope with the vast distances involved, many representations of the Solar System show orbits the same distance apart. In reality, with a few exceptions, the farther a planet or belt is from the Sun, the larger the distance between it and the previous orbit. For example, Venus is approximately 0.33 AU farther out than Mercury, while Saturn is 4.3 AU out from Jupiter, and Neptune lies 10.5 AU out from Uranus. Attempts have been made to determine a correlation between these orbital distances (see Titius-Bode law), but no such theory has been accepted. The Titius-Bode law (or Bodes law) is the observation that orbits of planets in the solar system closely follow a simple geometric rule. ...
Formation and evolution -
The Solar System is believed to have formed according to the nebular hypothesis, which holds that it emerged from the gravitational collapse of a giant molecular cloud 4.6 billion years ago. This initial cloud was likely several light-years across and probably birthed several stars.[7] Studies of ancient meteorites reveal traces of elements only formed in the hearts of very large exploding stars, indicating that the Sun formed within a star cluster, and in range of a number of nearby supernovae explosions. The shock wave from these supernovae may have triggered the formation of the Sun by creating regions of overdensity in the surrounding nebula, allowing gravitational forces to overcome internal gas pressures and cause collapse.[8] The theories concerning the formation and evolution of the Solar System are complex and varied, interweaving various scientific disciplines, from astronomy and physics to geology and planetary science. ...
Image File history File links Artists concept of a protoplanetary disk. ...
Image File history File links Artists concept of a protoplanetary disk. ...
A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ...
A planetary disk forming in the Orion Nebula In this artists conception, of a planet spins through a clearing in a nearby stars dusty, planet-forming disc In cosmogony, the nebular hypothesis is the currently accepted argument about how Earths Solar System formed. ...
A molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecules, most commonly molecular hydrogen (H2). ...
Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ...
The periodic table of the chemical elements A chemical element, or element, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. ...
This article or section does not cite its references or sources. ...
For other uses, see Supernova (disambiguation). ...
Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ...
Gas phase particles (atoms, molecules, or ions) move around freely Gas is one of the four major states of matter, consisting of freely moving atoms or molecules without a definite shape and without a definite volume. ...
The region that would become the Solar System, known as the pre-solar nebula,[9] had a diameter of between 7000 and 20,000 AU[7][10] and a mass just over that of the Sun (by between 0.1 and 0.001 solar masses).[11] As the nebula collapsed, conservation of angular momentum made it rotate faster. As the material within the nebula condensed, the atoms within it began to collide with increasing frequency. The centre, where most of the mass collected, became increasingly hotter than the surrounding disc.[7] As gravity, gas pressure, magnetic fields, and rotation acted on the contracting nebula, it began to flatten into a spinning protoplanetary disc with a diameter of roughly 200 AU[7] and a hot, dense protostar at the centre.[12][13] This article or section does not cite any references or sources. ...
This gyroscope remains upright while spinning due to its angular momentum. ...
For other uses, see Condensation (disambiguation). ...
Properties For other meanings of Atom, see Atom (disambiguation). ...
For the indie-pop band, see The Magnetic Fields. ...
A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ...
A Protostar is an object that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium. ...
Studies of T Tauri stars, young, pre-fusing solar mass stars believed to be similar to the Sun at this point in its evolution, show that they are often accompanied by discs of pre-planetary matter.[11] These discs extend to several hundred AU and reach only a thousand kelvins at their hottest.[14] Drawing of a T-Tauri star with a circumstellar accretion disk T Tauri stars are a class of variable stars named after their prototype - T Tauri. ...
For other uses, see Kelvin (disambiguation). ...
 Hubble image of protoplanetary disks in the Orion Nebula, a light-years-wide "stellar nursery" likely very similar to the primordial nebula from which our Sun formed. After 100 million years, the pressure and density of hydrogen in the centre of the collapsing nebula became great enough for the protosun to begin thermonuclear fusion. This increased until hydrostatic equilibrium was achieved, with the thermal energy countering the force of gravitational contraction. At this point the Sun became a full-fledged star.[15] Image File history File links M42proplyds. ...
Image File history File links M42proplyds. ...
The Hubble Space Telescope (HST) is a telescope in orbit around the Earth, named after astronomer Edwin Hubble. ...
The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated south of Orions Belt. ...
This article is about the chemistry of hydrogen. ...
A Protostar is an object that forms by contraction out of the gas of a giant molecular cloud in the interstellar medium. ...
The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ...
Hydrostatic equilibrium occurs when compression due to gravity is balanced by a pressure gradient which creates a pressure gradient force in the opposite direction. ...
From the remaining cloud of gas and dust (the "solar nebula"), the various planets formed. They are believed to have formed by accretion: the planets began as dust grains in orbit around the central protostar; then gathered by direct contact into clumps between one and ten metres in diameter; then collided to form larger bodies (planetesimals) of roughly 5 km in size; then gradually increased by further collisions at roughly 15 cm per year over the course of the next few million years.[16] This article or section does not cite any references or sources. ...
In astrophysics, the term accretion is used for at least two distinct processes. ...
Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks. ...
A centimetre (American spelling centimeter, symbol cm) is a unit of length that is equal to one hundredth of a metre, the current SI base unit of length. ...
The inner Solar System was too warm for volatile molecules like water and methane to condense, and so the planetesimals which formed there were relatively small (comprising only 0.6% the mass of the disc)[7] and composed largely of compounds with high melting points, such as silicates and metals. These rocky bodies eventually became the terrestrial planets. Farther out, the gravitational effects of Jupiter made it impossible for the protoplanetary objects present to come together, leaving behind the asteroid belt.[17] 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ...
Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ...
Methane is a chemical compound with the molecular formula . ...
Look up chemical compound in Wiktionary, the free dictionary. ...
The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ...
In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ...
This article is about metallic materials. ...
The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale. ...
For other uses, see Asteroid (disambiguation). ...
Farther out still, beyond the frost line, where more volatile icy compounds could remain solid, Jupiter and Saturn became the gas giants. Uranus and Neptune captured much less material and are known as ice giants because their cores are believed to be made mostly of ices (hydrogen compounds).[18][19] In astronomy or planetary physics, the frost line refers to a particular distance in the solar nebula from the central protosun where it is cool enough for hydrogen compounds such as water, ammonia, and methane to condense into solid ice grains. ...
This article does not cite any references or sources. ...
Once the young Sun began producing energy, the solar wind (see below) blew the gas and dust in the protoplanetary disk into interstellar space and ended the growth of the planets. T Tauri stars have far stronger stellar winds than more stable, older stars.[20][21] The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ...
A solar wind is a stream of particles (mostly high-energy protons ~ 500 keV) which are ejected from the upper atmosphere of a star (in the case of a star other than the Earths Sun, it may be called a stellar wind instead). ...
 Artist's conception of the future evolution of our Sun. Left: main sequence; middle: red giant; right: white dwarf Astronomers estimate that the Solar System as we know it today will last until the Sun begins its journey off of the main sequence. As the Sun burns through its supply of hydrogen fuel, it gets hotter in order to be able to burn the remaining fuel, and so burns it even faster. As a result, the Sun is growing brighter at a rate of roughly ten percent every 1.1 billion years.[22] Image File history File links Redgiantsun. ...
Image File history File links Redgiantsun. ...
Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ...
Around 6.4 billion years from now, the Sun's core will become hot enough to cause hydrogen fusion to occur in its less dense upper layers. This will cause the Sun to expand to roughly 100 times its current diameter, and become a red giant.[23] At this point, the sun will have cooled and dulled, because of its vastly increased surface area. 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. ...
Eventually, the Sun's outer layers will fall away, leaving a white dwarf, an extraordinarily dense object, half its original mass but only the size of the Earth.[24] This article or section does not adequately cite its references or sources. ...
Sun -
 The Sun as seen from Earth The Sun is the Solar System's parent star, and far and away its chief component. Its large mass gives it an interior density high enough to sustain nuclear fusion, which releases enormous amounts of energy, mostly radiated into space as electromagnetic radiation such as visible light. Sol redirects here. ...
Image File history File links Download high resolution version (1024x768, 38 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File links Download high resolution version (1024x768, 38 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
For other uses, see Density (disambiguation). ...
The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ...
Radiant energy is the energy of electromagnetic waves. ...
Layers of Atmosphere - not to scale (NOAA)[1] Outer space, sometimes simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. ...
This box: Electromagnetic (EM) radiation is a self-propagating wave in space with electric and magnetic components. ...
Visible light redirects here. ...
The Sun is classified as a moderately large yellow dwarf, but this name is misleading as, compared to stars in our galaxy, the Sun is rather large and bright. Stars are classified by the Hertzsprung-Russell diagram, a graph which plots the brightness of stars against their surface temperatures. Generally, hotter stars are brighter. Stars following this pattern are said to be on the main sequence; the Sun lies right in the middle of it. However, stars brighter and hotter than the Sun are rare, while stars dimmer and cooler are common.[25] Large solar flare recorded by SOHO EIT304 instrument in the ultraviolet. ...
For other uses, see Milky Way (disambiguation). ...
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. ...
For other uses, see Temperature (disambiguation). ...
Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ...
It is believed that the Sun's position on the main sequence puts it in the "prime of life" for a star, in that it has not yet exhausted its store of hydrogen for nuclear fusion. The Sun is growing brighter; early in its history it was 75 percent as bright as it is today.[26] Image File history File links Size of this preview: 534 × 599 pixelsFull resolution (723 × 811 pixel, file size: 26 KB, MIME type: image/gif) Hertzsprung-Russell Diagram from Richard Powells diagram at http://(remove this, site is blacklisted)anzwers. ...
Image File history File links Size of this preview: 534 × 599 pixelsFull resolution (723 × 811 pixel, file size: 26 KB, MIME type: image/gif) Hertzsprung-Russell Diagram from Richard Powells diagram at http://(remove this, site is blacklisted)anzwers. ...
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. ...
Calculations of the ratios of hydrogen and helium within the Sun suggest it is halfway through its life cycle. It will eventually move off the main sequence and become larger, brighter, cooler and redder, becoming a red giant in about five billion years.[27] At that point its luminosity will be several thousand times its present value. General Name, symbol, number helium, He, 2 Chemical series noble gases Group, period, block 18, 1, s Appearance colorless Standard atomic weight 4. ...
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. ...
This article does not cite any references or sources. ...
The Sun is a population I star; it was born in the later stages of the universe's evolution. It contains more elements heavier than hydrogen and helium ("metals" in astronomical parlance) than older population II stars.[28] Elements heavier than hydrogen and helium were formed in the cores of ancient and exploding stars, so the first generation of stars had to die before the universe could be enriched with these atoms. The oldest stars contain few metals, while stars born later have more. This high metallicity is thought to have been crucial to the Sun's developing a planetary system, because planets form from accretion of metals.[29] The globular cluster M80. ...
For other uses, see Universe (disambiguation). ...
The globular cluster M80. ...
The structure of the Sun The core of the Sun is considered to extend from the center to about 0. ...
An artists concept of a protoplanetary disc. ...
Interplanetary medium -
Along with light, the Sun radiates a continuous stream of charged particles (a plasma) known as the solar wind. This stream of particles spreads outwards at roughly 1.5 million kilometres per hour,[30] creating a tenuous atmosphere (the heliosphere) that permeates the Solar System out to at least 100 AU (see heliopause). This is known as the interplanetary medium. The Sun's 11-year sunspot cycle and frequent solar flares and coronal mass ejections disturb the heliosphere, creating space weather.[31] The Sun's rotating magnetic field acts on the interplanetary medium to create the heliospheric current sheet, the largest structure in the solar system.[32] 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...
Image File history File links Size of this preview: 768 × 600 pixelsFull resolution (866 × 676 pixel, file size: 172 KB, MIME type: image/gif) (All user names refer to en. ...
Image File history File links Size of this preview: 768 × 600 pixelsFull resolution (866 × 676 pixel, file size: 172 KB, MIME type: image/gif) (All user names refer to en. ...
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. ...
For other uses, see Light (disambiguation). ...
For other uses, see Plasma. ...
The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ...
The heliosphere is a bubble in space produced by the solar wind. ...
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...
It has been suggested that this article or section be merged with Schwabe-Wolf cycle. ...
A solar flare observed by Hinode in the G-band. ...
A composite image showing two CMEs (at 2 oclock and 8 oclock), with the sun at center. ...
Aurora australis observed by Discovery, May 1991. ...
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. ...
Earth's magnetic field protects its atmosphere from interacting with the solar wind. Venus and Mars do not have magnetic fields, and the solar wind causes their atmospheres to gradually bleed away into space.[33] The interaction of the solar wind with Earth's magnetic field creates the aurorae seen near the magnetic poles. Download high resolution version (874x576, 51 KB)NASA image of aurora australis taken from Space Shuttle in May 1991. ...
Download high resolution version (874x576, 51 KB)NASA image of aurora australis taken from Space Shuttle in May 1991. ...
Aurora borealis Polar aurorae are optical phenomena characterized by colorful displays of light in the night sky. ...
The magnetosphere shields the surface of the Earth from the charged particles of the solar wind. ...
Air redirects here. ...
The Aurora Borealis, or Northern Lights, shines above Bear Lake Aurora Borealis as seen over Canada at 11,000m (36,000 feet) Red and green Aurora in Fairbanks, Alaska Aurora Borealis redirects here. ...
The magnetosphere shields the surface of the Earth from the charged particles of the solar wind. ...
Cosmic rays originate outside the Solar System. The heliosphere partially shields the Solar System, and planetary magnetic fields (for planets which have them) also provide some protection. The density of cosmic rays in the interstellar medium and the strength of the Sun's magnetic field change on very long timescales, so the level of cosmic radiation in the Solar System varies, though by how much is unknown.[34] Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ...
The interstellar medium (or ISM) is the name astronomers give to the tenuous gas and dust that pervade interstellar space. ...
The interplanetary medium is home to at least two disc-like regions of cosmic dust. The first, the zodiacal dust cloud, lies in the inner Solar System and causes zodiacal light. It was likely formed by collisions within the asteroid belt brought on by interactions with the planets.[35] The second extends from about 10 AU to about 40 AU, and was probably created by similar collisions within the Kuiper belt.[36][37] “Space dust†redirects here. ...
Interplanetary dust cloud The interplanetary dust cloud has been studied for many years in order to understand its nature, origin, and relationship to solar systems (our own, as well as extrasolar systems). ...
The zodiacal light in the eastern sky before the beginning of morning twilight. ...
Inner Solar System The inner Solar System is the traditional name for the region comprising the terrestrial planets and asteroids. Composed mainly of silicates and metals, the objects of the inner Solar System huddle very closely to the Sun; the radius of this entire region is shorter than the distance between Jupiter and Saturn. This region was, in old parlance, denoted inner space; the area outside the asteroid belt was denoted outer space. In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ...
Inner planets -
The four inner or terrestrial planets have dense, rocky compositions, few or no moons, and no ring systems. They are composed largely of minerals with high melting points, such as the silicates which form their solid crusts and semi-liquid mantles, and metals such as iron and nickel, which form their cores. Three of the four inner planets (Venus, Earth and Mars) have substantial atmospheres; all have impact craters and tectonic surface features such as rift valleys and volcanoes. The term inner planet should not be confused with inferior planet, which designates those planets which are closer to the Sun than Earth is (i.e. Mercury and Venus). The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale. ...
Image File history File linksMetadata Download high resolution version (1500x653, 488 KB)Terrestrial planet size comparisons. ...
Image File history File linksMetadata Download high resolution version (1500x653, 488 KB)Terrestrial planet size comparisons. ...
This article is about the planet. ...
For other uses, see Venus (disambiguation). ...
This article is about Earth as a planet. ...
Adjectives: Martian Atmosphere Surface pressure: 0. ...
The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale. ...
Rock redirects here. ...
A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ...
A planetary ring is a ring of dust and other small particles orbiting around a planet in a flat disc-shaped region. ...
In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ...
Earth cutaway from core to exosphere. ...
Earth cutaway from core to exosphere. ...
General Name, symbol, number iron, Fe, 26 Chemical series transition metals Group, period, block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ...
For other uses, see Nickel (disambiguation). ...
The planetary core consists of the innermost layer(s) of a planet. ...
For other uses, see Atmosphere (disambiguation). ...
Tycho crater on Earths moon. ...
The tectonic plates of the world were mapped in the second half of the 20th century. ...
African Rift Valley. ...
Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ...
The terms inferior planet and superior planet were coined by Copernicus to distinguish a planets orbits size in relation to the Earths. ...
- Mercury
- Mercury (0.4 AU) is the closest planet to the Sun and the smallest planet (0.055 Earth masses). Mercury has no natural satellites, and its only known geological features besides impact craters are "wrinkle-ridges", probably produced by a period of contraction early in its history.[38] Mercury's almost negligible atmosphere consists of atoms blasted off its surface by the solar wind.[39] Its relatively large iron core and thin mantle have not yet been adequately explained. Hypotheses include that its outer layers were stripped off by a giant impact, and that it was prevented from fully accreting by the young Sun's energy.[40][41]
- Venus
- Venus (0.7 AU) is close in size to Earth (0.815 Earth masses) and, like Earth, has a thick silicate mantle around an iron core, a substantial atmosphere and evidence of internal geological activity. However, it is much drier than Earth and its atmosphere is ninety times as dense. Venus has no natural satellites. It is the hottest planet, with surface temperatures over 400 °C, most likely due to the amount of greenhouse gases in the atmosphere.[42] No definitive evidence of current geological activity has been detected on Venus, but it has no magnetic field that would prevent depletion of its substantial atmosphere, which suggests that its atmosphere is regularly replenished by volcanic eruptions.[43]
- Earth
- Earth (1 AU) is the largest and densest of the inner planets, the only one known to have current geological activity, and the only planet known to have life. Its liquid hydrosphere is unique among the terrestrial planets, and it is also the only planet where plate tectonics has been observed. Earth's atmosphere is radically different from those of the other planets, having been altered by the presence of life to contain 21% free oxygen.[44] It has one satellite, the Moon, the only large satellite of a terrestrial planet in the Solar System.
- Mars
- Mars (1.5 AU) is smaller than Earth and Venus (0.107 Earth masses). It possesses a tenuous atmosphere of mostly carbon dioxide. Its surface, peppered with vast volcanoes such as Olympus Mons and rift valleys such as Valles Marineris, shows geological activity that may have persisted until very recently. Its red color comes from rust in its iron-rich soil.[45] Mars has two tiny natural satellites (Deimos and Phobos) thought to be captured asteroids.[46]
This article is about the planet. ...
A natural satellite is an object that orbits a planet or other body larger than itself and which is not man-made. ...
A wrinkle-ridge is a type of feature commonly found on Lunar mares. ...
For other uses, see Venus (disambiguation). ...
For other uses, see Celsius (disambiguation). ...
Top: Increasing atmospheric CO2 levels as measured in the atmosphere and ice cores. ...
This article is about Earth as a planet. ...
This article is about life in general. ...
The movement of water around, over, and through the Earth is called the water cycle, a key process of the hydrosphere. ...
The tectonic plates of the world were mapped in the second half of the 20th century. ...
General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colourless (gas) colourless (liquid) Standard atomic weight 15. ...
This article is about Earths moon. ...
Adjectives: Martian Atmosphere Surface pressure: 0. ...
Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ...
This article is about the volcano on Mars and Solar Systems tallest mountain in Latin, For other uses, see Olympus (disambiguation). ...
Valles Marineris cuts a wide swath across the face of Mars Valles Marineris (Latin for Mariner Valley, named after the Mariner 9 Mars orbiter of 1971-72 which discovered it. ...
Deimos (IPA or ; Greek Δείμος: Dread), is the smaller and outermost of Mars’ two moons, named after Deimos from Greek Mythology. ...
Phobos (IPA: or [ˈfoʊ.bəs]) (systematic designation: ) is the larger and closer of Mars two moons (the other being Deimos). ...
For other uses, see Asteroid (disambiguation). ...
Asteroid belt -
Main article: Asteroid belt
 Image of the main asteroid belt and the Trojan asteroids Asteroids are mostly small Solar System bodies composed mainly of rocky and metallic non-volatile minerals. For other uses, see Asteroid (disambiguation). ...
Image File history File links Download high-resolution version (768x768, 188 KB)The inner Solar System, from the Sun to Jupiter. ...
Image File history File links Download high-resolution version (768x768, 188 KB)The inner Solar System, from the Sun to Jupiter. ...
For other uses, see Asteroid (disambiguation). ...
The main asteroid belt occupies the orbit between Mars and Jupiter, between 2.3 and 3.3 AU from the Sun. It is thought to be remnants from the Solar System's formation that failed to coalesce because of the gravitational interference of Jupiter.
Asteroids range in size from hundreds of kilometres across to microscopic. All asteroids save the largest, Ceres, are classified as small Solar System bodies, but some asteroids such as Vesta and Hygieia may be reclassed as dwarf planets if they are shown to have achieved hydrostatic equilibrium. Spectral type: G[8] Absolute magnitude: 3. ...
4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ...
10 Hygiea (hye-jee-a or hi-jee-a) is the fourth largest Main belt asteroid with a diameter of 407 km. ...
Hydrostatic equilibrium occurs when compression due to gravity is balanced by a pressure gradient which creates a pressure gradient force in the opposite direction. ...
The asteroid belt contains tens of thousands, possibly millions, of objects over one kilometre in diameter.[47] Despite this, the total mass of the main belt is unlikely to be more than a thousandth of that of the Earth.[48] The main belt is very sparsely populated; spacecraft routinely pass through without incident. Asteroids with diameters between 10 and 10-4 m are called meteoroids.[49] Technicians work on the Ulysses space probe. ...
This article is about the unit of length. ...
“Meteor†redirects here. ...
- Ceres
- Ceres (2.77 AU) is the largest body in the asteroid belt and is classified as a dwarf planet. It has a diameter of slightly under 1000 km, large enough for its own gravity to pull it into a spherical shape. Ceres was considered a planet when it was discovered in the 19th century, but was reclassified as an asteroid in the 1850s as further observation revealed additional asteroids.[50] It was again reclassified in 2006 as a dwarf planet.
- Asteroid groups
- Asteroids in the main belt are divided into asteroid groups and families based on their orbital characteristics. Asteroid moons are asteroids that orbit larger asteroids. They are not as clearly distinguished as planetary moons, sometimes being almost as large as their partners. The asteroid belt also contains main-belt comets[51] which may have been the source of Earth's water.
Trojan asteroids are located in either of Jupiter's L4 or L5 points (gravitationally stable regions leading and trailing a planet in its orbit); the term "Trojan" is also used for small bodies in any other planetary or satellite Lagrange point. Hilda asteroids are in a 2:3 resonance with Jupiter; that is, they go around the Sun three times for every two Jupiter orbits. Image File history File linksMetadata Ceres_optimized. ...
Image File history File linksMetadata Ceres_optimized. ...
Spectral type: G[8] Absolute magnitude: 3. ...
Artists impression of Pluto (background) and Charon (foreground). ...
Minor planet is the official term for asteroids and trans-Neptunian objects. ...
243 Ida and its moon Dactyl An asteroid moon is an asteroid that orbits another asteroid. ...
Main-belt comets are bodies orbiting within the (main) asteroid belt which show cometary activity during a part of their orbit. ...
Image of the Trojan asteroids in front of and behind Jupiter along its orbital path. ...
A contour plot of the effective potential (the Hills Surfaces) of a two-body system (the Sun and Earth here), showing the five Lagrange points. ...
Hilda asteroids are asteroids with a semi-major axis between 3. ...
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other. ...
The inner Solar System is also dusted with rogue asteroids, many of which cross the orbits of the inner planets. Computer model of the Apollo Asteroid 6489 Golevka Near-Earth asteroids (NEAs) are asteroids whose orbits are close to Earths orbit. ...
Mid Solar System The middle region of the Solar System is home to the gas giants and their planet-sized satellites. Many short period comets, including the centaurs, also lie in this region. It has no traditional name; it is occasionally referred to as the "outer Solar System", although recently that term has been more often applied to the region beyond Neptune. The solid objects in this region are composed of a higher proportion of "ices" (water, ammonia, methane) than the rocky denizens of the inner Solar System. The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ...
Outer planets -
 From top to bottom: Neptune, Uranus, Saturn, and Jupiter (not to scale) The four outer planets, or gas giants (sometimes called Jovian planets), collectively make up 99 percent of the mass known to orbit the Sun. Jupiter and Saturn's atmospheres are largely hydrogen and helium. Uranus and Neptune's atmospheres have a higher percentage of “ices”, such as water, ammonia and methane. Some astronomers suggest they belong in their own category, “ice giants.”[52] All four gas giants have rings, although only Saturn's ring system is easily observed from Earth. The term outer planet should not be confused with superior planet, which designates planets outside Earth's orbit (the outer planets and Mars). This article does not cite any references or sources. ...
Image File history File links Download high resolution version (509x655, 33 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): European Space Operations Centre Gas giant Solar system Encyclopedia Astronautica Meteoroid Marshall Space Flight Center Stanford torus EADS...
Image File history File links Download high resolution version (509x655, 33 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): European Space Operations Centre Gas giant Solar system Encyclopedia Astronautica Meteoroid Marshall Space Flight Center Stanford torus EADS...
This article does not cite any references or sources. ...
Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ...
For other uses, see Ammonia |
