Uranus Discovered

Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. Uranus is similar in composition to Neptune, and both have different bulk chemical composition from that of the larger gas giants Jupiter and Saturn. Therefore, astronomers increasingly place them in a separate category called "ice giants". It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of −224.2 °C, and has a complex, layered cloud structure. The interior of Uranus is mainly composed of ices and rock.

Like the other giant planets, Uranus has a ring system, a magnetosphere, and numerous moons. The Uranian system has a unique configuration among those of 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 therefore lie where most other planets have their equators.

Though Uranus is visible to the naked eye like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit. Sir William Herschel announced its discovery on March 13, 1781, expanding the known boundaries of the Solar System for the first time in history. Uranus was the first planet discovered with a telescope.

http://en.wikipedia.org/wiki/Uranus
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