The interior of Uranus is mainly composed of gas.
Uranus . Uranus 's atmosphere is similar to Jupiter 's and Saturn 's in its primary composition of hydrogen and helium , but it contains more `` ices '' such as water , ammonia , and methane , along with traces of other hydrocarbons . It is the coldest planetary atmosphere in the Solar System , with a minimum temperature of 49 K , 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 .