A view of Uranus by Voyager 2, as the spacecraft left the planet behind and set forth on the cruise to Neptune.  Even at this extreme angle, Uranus retains the pale blue-green color seen by ground-based astronomers and recorded by Voyager during its historic encounter. This color results from the presence of methane in Uranus' atmosphere; the gas absorbs red wavelengths of light, leaving the predominant hue seen here.  Image credit: NASA