Image comparing the size of Earth (left) with the planet Uranus. Uranus is the seventh planet from the Sun, with an average distance from it of 19.2 times the Earth-Sun distance. A fluid world of mostly hydrogen and helium, it is rich in ices of methane, water and ammonia, causing some astronomers to label it (along with Neptune) an ice giant. With a diameter of four times that of the Earth, Uranus is the Solar System's third largest planet (after Jupiter and Saturn).