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...eous [[protoplanetary disk]] around the young star. This may give birth to planets in certain circumstances, which are not well known. Thus the formation of p ...can migrate over long distances during or after their formation. The [[ice giant]]s like [[Uranus]] and [[Neptune]] are thought to be failed cores, which fo ...

| title=Are beryllium abundances anomalous in stars with giant planets? ...and so it is thought to be less likely to host [[terrestrial planets|rocky planets]]. Observations have detected more than 10 times as much dust surrounding T ...

...llion]] years ago with the [[gravitation]]al collapse of a small part of a giant [[molecular cloud]]. Most of the collapsing mass collected in the centre, f ...e dawn of the [[space age]] in the 1950s and the discovery of [[extrasolar planets]] in the 1990s, the models have been both challenged and refined to account ...

...ts, [[Jupiter]], [[Saturn]], [[Uranus]] and [[Neptune]], also called the [[gas giants]], are composed largely of hydrogen and helium and are far more mass ...ugh to have been rounded by their own gravity, and are thus termed [[dwarf planets]]. The hypothetical [[Oort cloud]], which acts as the source for [[long-per ...

...small terrestrial planets remains a possibility, the existence of massive planets has been largely discounted, and Van de Kamp's specific claims overturned. ...were apparently refined in a 1969 paper. Later that year he suggested two planets of 1.1 and 0.8 Jupiter masses.<ref>{{cite journal | author = Van de Kamp, P ...

...[[methane]]. Astronomers sometimes categorize Uranus and Neptune as "[[ice giant]]s" in order to emphasize these distinctions.<ref name=atmo/> The interior | url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Neptune&Display=OverviewLong ...

...ic]] in nature and led to the formation of the canyons, which are actually giant cracks in the ice crust.<ref name=Croft1989/> The canyons obliterated parts ...sted around Uranus for some time after its formation or was created by the giant impact that most likely gave Uranus its large [[obliquity]].<ref name=Mousi ...

...oloured green, while scattered objects are coloured orange. The four outer planets are blue. Neptune's few known [[Trojan asteroid]]s are yellow, while Jupite ...s as massive.<ref name=beyond>{{cite web|title=The Solar System Beyond The Planets|author=Audrey Delsanti and David Jewitt|work=Institute for Astronomy, Unive ...

| accessdate = 2006-08-04 }}</ref> expand to become a [[red giant]], in some cases fusing heavier [[chemical element|elements]] at the core o ...stars into [[constellations]] and used them to track the motions of the [[planets]] and the inferred position of the Sun.<ref name="forbes">{{cite book ...

...planetary orbits are close to face-on as observed from Earth, more massive planets could have evaded detection by the radial velocity method.</ref> The detect | url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sun&Display=Facts&System=Metric ...

...is not known to exist on any other planet's surface.<ref group=note>Other planets in the Solar System are either too hot or too cold to support liquid water. ...detected in the atmosphere of only one extrasolar planet, and it is a gas giant. See: {{cite journal ...

...">{{cite web|url=http://www.resa.net/nasa/ganymede.htm|title=Ganymede: the Giant Moon|work=Wayne RESA|accessdate=2007-12-31}}</ref> The analysis of high-res ...ars estimated for Callisto. The Jovian subnebula may have been relatively "gas-starved" when the Galilean satellites formed; this would have allowed for t ...

...more massive of these, Sirius B, consumed its resources and became a [[red giant]] before shedding its outer layers and collapsing into its current state as ...h'. The authors proposed this was further evidence Sirius B had been a red giant at the time.<ref>{{cite journal ...

| title=A Field Guide to Stars and Planets ...fe span. After leaving the main sequence, Vega will become a class-M [[red giant]] and shed much of its mass, finally becoming a [[white dwarf]]. At present ...

| url = http://solarsystem.jpl.nasa.gov/planets/profile.cfm?Object=Mars&Display=Facts&System=Metric ...ist and were instead explained as [[optical illusion]]s. Still, of all the planets in the Solar System other than Earth, Mars is the most likely to harbor liq ...

...on]] and [[oxygen]] in its core by the [[triple-alpha process]]. If a red giant has insufficient mass to generate the core temperatures required to fuse [[ ...els of a white dwarf. Both models treat the white dwarf as a cold [[Fermi gas]] in hydrostatic equilibrium. The average molecular weight per electron, ' ...