16. Neptune

16. Neptune

Courtesy of NASA/JPL

http://photojournal.jpl.nasa.gov/catalog/PIA01142


Neptune's atmosphere is similar to the other gas giants in the Solar System. It consists mainly of hydrogen and helium with trace amounts of methane, water, and ammonia. But Neptune has a larger portion of methane ice in it's upper atmosphere which gives it its distinctive blue color.
Neptune has a long-lasting storm, called the Great Dark Spot, similar to the Great Red
Spot on Jupiter. The fastest winds in the Solar System have been clocked on Neptune at 2,400 km/h (1,500 mph).
The small white spot below the Great Dark Spot is a bright feature the Voyager scientists nicknamed Scooter.