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The Planet Uranus is the third largest planet in the solar system, is a Gas Giant and is the seventh planet from the sun. Planet Uranus has rings like Planet Jupiter, Saturn and Neptune.

It was discovered by William Herschel on March 13, 1781 and was the first planet discovered in modern times. It is also the first planet discovered with a telescope as opposed to the naked eye.

The Planet Uranus has been visited by the Voyager 2 spacecraft

Facts about Planet Uranus
* Diameter: 51,500 km (32,000 miles)

* Temperature: -197.15 C (-322.87 F)

* Orbit: Takes 84 years to complete an orbit.

* Average Distance: 2,870,972,200 km (1,783,939,400 miles - 19.2 AU) from Sun

* Mass: 8.6849 x 1025 kg

* Moons: 27

* Period of Rotation: 17.24 hours (retrograde: spins backwards compared to most other planets)
Uranus' atmosphere is about 83% hydrogen, 15% helium and 2% methane. There are also traces of water and ammonia. The planet's atmospheric details are very difficult to see in visible light. The methane gas above the cloud layers gives it a blue-green colour.

Johann E. Bode, a German astronomer, named the planet after the Greek god of the sky.

Uranus is the only planet in our Solar System to spin on its side. The axis of rotation tilt is 98 degrees. The severe tilt to its rotational axis may have resulted from a great collision long ago.

Uranus is a 'Gas Giant' with no solid surface. It may have a small, silicate-rich core, but most of its gas consists of water, ammonia and methane. Its surface area is about 8,115,600,000 km2 .

More than 80 percent of the mass of Uranus is contained in an extended liquid core consisting primarily of 'icy' materials (water, methane and ammonia) with higher-density material at depth.

If you know where to look, it can occasionally be spotted with the naked eye, however, it can be hard to see due to the similarity of the background stars.

The only spacecraft to visit Planet Uranus was the Voyager 2 spacecraft in a flyby in 1986. It discovered 10 moons and two rings in addition to studying moons and rings previously seen from Earth.

Moons of Uranus
The Planet Uranus has many moons. Five of largest are Miranda, Titania, Oberon, Umbriel, Ariel. The largest moon is Titania with a radius of only 788.9 km (less than half that of our Moon).

The Titania and Oberon were discovered by William Herschel in 1787. Ariel and Umbriel were discovered by William Lassell in 1851. John Herschel (William Herschel's son) gave the four then known moons their names in 1852. In 1948 Gerard Kuiper discovered the moon Miranda.

Many moons of Uranus have been named for characters in the works of William Shakespeare and Alexander Pope.

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