20-03-2018 : Uranus The Solar System A commemorative postage stamp

Uranus is the 7th planet from the Sun. 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 (-224⁰C). Uranus’s mass is roughly 14.5 times that of earth. Its diameter is four times that of Earth.