Talk:Uranus/climate subpage
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Sorry for this but is this page still in use? —Preceding unsigned comment added by Nergaal (talk • contribs) 09:58, 31 January 2008 (UTC)
Image taken by the Voyager 2 spacecraft | |||||||||||||||||||
Discovery | |||||||||||||||||||
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Discovered by | William Herschel | ||||||||||||||||||
Discovery date | March 13, 1781 | ||||||||||||||||||
Designations | |||||||||||||||||||
Adjectives | Uranian | ||||||||||||||||||
Symbol | |||||||||||||||||||
Orbital characteristics[1][2] | |||||||||||||||||||
Epoch J2000 | |||||||||||||||||||
Aphelion | 3,004,419,704 km 20.08330526 AU | ||||||||||||||||||
Perihelion | 2,748,938,461 km 18.37551863 AU | ||||||||||||||||||
2,876,679,082 km 19.22941195 AU | |||||||||||||||||||
Eccentricity | 0.044405586 | ||||||||||||||||||
369.66 days[3] | |||||||||||||||||||
Average orbital speed | 6.81 km/s[3] | ||||||||||||||||||
142.955717° | |||||||||||||||||||
Inclination | 0.772556° 6.48° to Sun's equator | ||||||||||||||||||
73.989821° | |||||||||||||||||||
Known satellites | 27 | ||||||||||||||||||
Physical characteristics | |||||||||||||||||||
Equatorial radius | 25,559 ± 4 km 4.007 Earths[4][5] | ||||||||||||||||||
Polar radius | 24,973 ± 20 km 3.929 Earths[4][5] | ||||||||||||||||||
8.1156×109 km²[6][5] 15.91 Earths | |||||||||||||||||||
Volume | 6.833×1013 km³[3][5] 63.086 Earths | ||||||||||||||||||
Mass | 8.6810 ± 13×1025 kg GM=5,793,939 ± 13 km³/s² 14.536 Earths[7] | ||||||||||||||||||
Mean density | 1.290 g/cm³[7][5] | ||||||||||||||||||
8.69 m/s²[3][5] 0.886 g | |||||||||||||||||||
21.3 km/s[3][5] | |||||||||||||||||||
−0.71833 day 17 h 14 min 24 s[4] | |||||||||||||||||||
Equatorial rotation velocity | 2.59 km/s 9,320 km/h | ||||||||||||||||||
97.77°[4] | |||||||||||||||||||
North pole right ascension | 17 h 9 min 15 s 257.311°[4] | ||||||||||||||||||
North pole declination | −15.175°[4] | ||||||||||||||||||
Albedo | 0.300 (bond) 0.51 (geom.)[3] | ||||||||||||||||||
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Atmosphere[9][10][11][12] | |||||||||||||||||||
27.7 km [3] | |||||||||||||||||||
Composition by volume | (Below 1.3 bar)
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Uranus (/jʊˈreɪnəs, ˈjʊərənəs/)[14] is the seventh planet from the Sun, the third largest and fourth most massive planet in the solar system. It is named after the ancient Greek deity of the sky (Uranus, Οὐρανός), the father of Kronos (Saturn) and grandfather of Zeus (Jupiter). Uranus was the first planet discovered in modern times. Though it is visible to the naked eye like the five classical planets, it was never recognised as a planet by ancient observers due to its dimness.[15] Sir William Herschel announced its discovery on March 13, 1781, expanding the known boundaries of the solar system for the first time in modern history. This was also the first discovery of a planet made using a telescope.
Uranus and Neptune have different internal and atmospheric compositions from those of the larger gas giants Jupiter and Saturn. As such, astronomers sometimes place them in a separate category, the "ice giants". Uranus' atmosphere, while still composed primarily of hydrogen and helium, contains a higher proportion of "ices" such as water, ammonia and methane, along with the usual traces of hydrocarbons. It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K, and has a complex layered cloud structure, in which water is thought to make up the lowest clouds, while methane makes up the uppermost layer of clouds.[9]
Like the other giant planets, Uranus has a ring system, a magnetosphere, and numerous moons. The Uranian system has a unique configuration among the planets because its axis of rotation is tilted sideways, nearly into the plane of its revolution about the Sun; its north and south poles lie where most other planets have their equators.[16] Seen from Earth, Uranus' rings appear to circle the planet like an archery target and its moons revolve around it like the hands of a clock. In 1986, images from Voyager 2 showed Uranus as a virtually featureless planet in visible light without the cloud bands or storms associated with the other giants.[16] However, ground-based observers have seen signs of seasonal change and increased weather activity in recent years as Uranus approaches its equinox. The wind speeds on Uranus can reach 250 m/s.[17]