Uranus

The seventh planet of the solar system in order from the Sun is just bright enough to be seen by the naked eye from Earth. It has about 17 moons.

Image of Uranus NASA and Erich Karkoschka, University of Arizona

Uranus, like Jupiter, Saturn and Neptune, is a gas giant planet, made almost entirely of hydrogen and helium. Its diameter is four times the Earth's. It probably has a small rocky core at the center of the planet, surrounded by a thick icy mantle of frozen water, methane and ammonia. Above this is an atmosphere of hydrogen and helium.

Uranus has a series of narrow rings only a few kilometers wide and not visible from Earth.