Uranus is often called the emerald planet of our solar system. It is called this because its atmosphere contains hydrogen and helium, like the two previously mentioned planets, but it also contains about.4% methane. Since methane strongly absorbs red light, the reflected light from the planet is mostly blue, green, and yellow light. The result is that Uranus appears green.
In 1977 at least nine rings were discovered around Uranus. They were all very thin and similar to the single rings around Jupiter. The rings are composed of dark material which reflects less light than a blackboard.
At 21 years in length, Uranus, has the longest known winter in the solar system. The harsh winter temperature is -363° F. The 23.5° tilt that gives us our four seasons, is 98° on Uranus, thereby giving Uranus the dubious title longest winter/summer in the solar system. Uranus has five known moons.