Uranus, discovered in 1781 by William Herschel, is the third largest planet. As with the other Jovian planets, Uranus has 15 moons orbiting it. The methane in Uranus' atmosphere absorbs red light, giving Uranus its blue appearance. Uranus, like Jupiter, also has a ring system, although not nearly as pronounced as Saturn's.

The strangest feature of Uranus is actually its axis of rotation. Uranus it tipped 90 degrees and sits on its side, appearing to roll around the sun. It is believed that this tilt is a result of a collision with a planet size body many years ago. This has a very interesting affect on the planet's magnetic field. Uranus' magnetic field is tilted about 60 degrees of the planet's axis. This, coupled with the planets odd rotation, results in a magnetic field that spirals out behind the planet.

Mass 8.7e+25 kg

Equatorial radius 25,559 km

Mean density 1.29 gm/cm^3

Mean distance from the Sun 2,870,990,000 km

Rotational period -17.9 hours

Orbital period 84.01 years

Tilt of axis 98.00 degrees

Equatorial surface gravity 7.8 m/sec^2

Mean cloud temperature -193°C

Atmospheric composition: Hydrogen 83%

Atmospheric composition : Helium 15%

Atmospheric composition : Methane 2%