The planet Uranus is often given the nickname "ice giant." This is because of the planet's cold atmosphere brought about by the mix of methane, water and ammonia ices that make up 80 percent of the planet's mass.
The name Uranus was derived from the name of the Greek sky deity called Ouranos. This name was given by the German astronomer Johann Bode after he detailed the orbit of Uranus. However, it was British astronomer William Herschel who discovered the planet on March 13, 1781. Herschel originally named the planet "Georgium Sidus," which translates to mean "the Georgian Planet," in honor King George III of England.