Uranus (ˈjʊɹənəs)

Uranus is an ice giant planet in the Solar System, the second-furthest from the Sun at number 7. It is very cold and windy, and has the third largest diameter in its system. It also is the only planet in its system to rotate almost completely on its side.

Geography

Most of this cyan-colored planet is made of supercritical water, ammonia, and methane, known as volatiles or 'ice'. Like the gas giants, beneath its volatile mantle is a dense, rocky core. Uranus also has a very dark ring system and 27 moons orbiting the planet. It is the least massive of the giant planets in the Solar System, with a mass about 4.5 times that of Earth, but its diameter is only the second-smallest, behind Neptune.
Uranus' mantle is subject to extreme pressures, which may break up methane molecules, leaving carbon atoms to rain as diamond crystals. The very base of this mantle is under enough pressure to contain an ocean of liquid metallic carbon, potentially with solid sections in the form of floating 'diamond-bergs'.

Climate

Like the gas giants, Uranus' atmosphere is made up of mostly hydrogen and helium, with enough gaseous methane to give the planet its cyan hue. Uranus' atmosphere, however, is notably bland when compared to the other giant planets, with only 10 cloud features observed by Voyager 2 in 1986. This is likely caused by Uranus' comparatively lower internal heat.

History

Uranus is visible to the naked eye, but it is so dim and slow that it was never recognized as a planet by ancient civilizations. This changed in March of 1781, when Uranus became the first planet to be classified with a telescope. Exploration began in 1986 with Voyager 2's 50,600 mile flyby, making detailed observations of its first 5 moons and discovering its next ten. The first manned mission to Uranus orbited the planet three times before landing on its closest round moon known as Miranda on February 24th, 2047.

Designations

Classification	Planet
Type	Ice giant
Alternative names	Sol VII
Adjective	Uranian

Location Data

Star	Sun
Moons	27
Star system	Solar System
Spiral Arm	Orion Arm
Galaxy	Milky Way

Orbit & Rotation

Rotation period	0.713 standard days 17h 14m 24s
Orbital period	84.02 standard years

Atmosphere

Composition by volume

83% hydrogen 15% helium 2% methane 1% trace gases