Two Hours Before Neptune

The Voyager 2 spacecraft took this photograph two hours before reaching its destination, en route to Neptune in 1989. Long white clouds are clearly visible in Neptune's atmosphere.

Neptune's atmosphere is largely composed of helium and hydrogen. These are not visible, so the blue atmosphere we see in the photograph is not there. The blue color is caused by the small amount of methane in the atmosphere, which absorbs the red. Neptune also has the highest winds in the Solar System, reaching speeds of up to 2000 km/h.

Image Credit: Voyager 2, NASA