Uranus with 5 Moons ©Spaceshots Art Print Buy at AllPosters.com

1,783 million miles from sun. Diameter: 31,000 miles. Moons: 15. Length of year: 84 Earth years.

Uranus' atmosphere is made up of hydrogen, helium, and methane. The temperature in the upper atmosphere is very cold. The cold methane gas is what gives Uranus its blue-green color. The rapid rotation of Uranus causes winds up to 600 kilometers per hour to blow in its atmosphere.

Perhaps because of a collision with a large object long ago, Uranus orbits at an extreme tilt of 98 degrees, sort of on its side. The planet is the only one in our solar system that lays on its side instead of standing straight up. This causes one pole to point toward the sun for decades, giving the planet strange seasons. Uranus has 18 known satellites (the most recent was found in May, 1998) and a faint set of rings.

One of the mysterious gas giants, Uranus has rings like Saturn, but they are very faint and weren't discovered until the planet was visited by the Voyager spacecraft. Uranus has eleven known rings which contain dark, boulder-sized particles.

Uranus has 18 known moons. Some of these moons are less than 90 miles wide and black as coal. Three more moons may have been found by astronomers.