Since Neptune is so far away, much of what we know about this gas giant comes from Voyager 2, the onlyspacecraft to visit this planet. It arrived at the planet on August 25, 1989 and imaged much of the surface on Neptune. The images gathered revealed much about Neptune's atmosphere, interior, rings, moons and surface features.
One of the most interesting discoveries of the Voyager 2 is finding The Great Dark Spot and the Scooter. These two features reveal much about Neptune's erratic and dynamic surface activity, as the wind speeds around these two areas reach up to 2,000 kilometers an hour (1,200 miles per hour). Even more bizarre, the Great Dark Spot imaged by Voyager 2 has recently disappeared! A New Dark Spot has formed in which scientists speculate will not last long either.
Voyager 2 has also photographed twisted rings on Neptune and observed cirrus-clouds on the surface. These discoveries helped scientists understand more about the nature of Neptune's surface and interior.
The Discoveries of Voyager 
