Uranus

Uranus [1] named after the Greek god of the sky was discovered on March 13, 1781, (the first planet found using a telescope) by British astronomer William Herschel who originally believed it to be a comet. It's the seventh planet from the Sun orbiting at a distance of 2,872,279,123 km or 19.2 AU, the third largest with a diameter of 51,118 km and the fourth most massive.

Voyager 2 gathered valuable information as it passed by on its way to Neptune. The spacecraft's closest approach was on January 24, 1986.

Uranus like Neptune is often referred to as a gas giant, but like its neighbor a more appropriate title would probably be ice giant. The atmosphere is thin (as compared to the true gas giants Jupiter and Saturn) mostly hydrogen (83%) helium (15%) and Methane, Acetylene and other hydrocarbons (2%) with a mean cloud temperature of -193 °C. Its interior is composed primarily of water, ammonia and methane ices surrounding a small rocky core.

Uranus has an axial tilt of 97.77 degrees, which places it on its side with respect to the plane of the ecliptic (its poles are where most planets have their equators).

Uranus has a faint ring system [2] composed of eleven darkly colored narrow bands, 1986 U2R, Six, Five, Four, Alpha, Beta, Eta, Gamma, Delta, 1986 U1R and the furthest out Epsilon which orbits at a distance of 51,140 km from the planets center.

To date Uranus has 27 known moons: Cordelia, Ophelia, Blanca, Cressida, Desdemona, Juliet, Portia, Rosalind, Mab, Belinda, Perdita, Puck, Cupid, Miranda, Francisco, Ariel, Umbriel, Titania, Oberon, Caliban, Stephano, Trinculo, Sycorax, Margaret, Prospero, Setebos and Ferdinand.

[1] The Greek god of the sky is actually Ouranos, Uranus is the Latinized version.

[2] A planetary ring is a flat disk shaped band composed of rock or ice dust, larger rocks, boulders and ice chunks which circle in a planet's equatorial plane.

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