The planet Uranus was initially named "Georgium Sidus" after King George III, who reigned over Britain during the discovery of the planet in 1781 by British astronomer Sir William Herschel. However, the name did not gain universal acceptance and eventually, it was renamed after the ancient Greek deity Uranus, the personification of the sky. Uranus is the seventh planet from the Sun and is known for its tilted axis, which causes it to rotate on its side. It has a distinct blue-green color due to the presence of methane gas in its atmosphere. Uranus has 27 known moons and several faint, narrow rings. It is also one of the four gas giants in our solar system, along with Jupiter, Saturn, and Neptune.