Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K (−224.2 °C), and has a complex, layered cloud structure with water thought to make up the lowest clouds and methane the uppermost layer of clouds. The interior of Uranus is mainly composed of ices and rock. Like the other giant planets, Uranus has a ring system, a magnetosphere, and numerous moons. Uranus is the only planet whose name is derived from a figure from Greek mythology, from the Latinized version of the Greek god of the sky Ouranos.
Uranus (Ancient Greek: Οὐρανός, Ouranos meaning "sky" or "heaven") was the primal Greek god personifying the sky. His equivalent in Roman mythology was Caelus. In Ancient Greek literature, Uranus or Father Sky was the son and husband of Gaia, Mother Earth.