Astronomers describe Uranus like a uniform blue-green globe.
The probe Voyager 2, when it flew over it in 1968, did not show anything of its surface, except some slight, white clouds.
Astronomers classify Uranus as a "gaseous giant" even though it is mainly composed of a mixture of hot water, ammonia and methane.
A thick layer of gas covers the inner fluid.
Uranus was discovered in 1781 by William Herschel, a German music teacher and amateur astronomer, who lived in England.
Herschel named it "Star of George", in honour of king George III of England, but its name was later changed in Uranus, the Greek god of heaven.
