Tour the solar system: Uranus

Uranus' first visible dark spot indicates strong winds on the planet.

NASA/ESA/L. Sromovsky and P. Fry (University of Wisconsin-Madison)/H. Hammel (Space Science Institute)/K. Rages (SETI Institute)

The seventh planet from the Sun, Uranus is named after the Greek god of the sky. British astronomer William Herschel discovered it with the aid of a telescope March 13, 1781. Uranus is the third-largest planet in diameter in our solar system (with Jupiter and Saturn being larger planets). Much of the seventh planet is composed of hydrogen, helium, methane, ammonia, and water. Uranusò?? blue-green color is actually a result of the planetò??s methane, which absorbs red wavelengths and reflects blue. The planet likely has a small rocky core.