The Great Dark Spot, was a storm first spotted on Neptune in 1989 by Voyager 2, much like Jupiter's Giant Red Spot. The main difference between Neptune's storms and the great red spot on Jupiter, is that the latter has lasted for hundreds of years, whereas Neptune's storms are much shorter lived. There have been a few similar storms spotted since the great dark spot was first observed. These storms are large anti-cyclonic events. Neptune appears to spend around half of its existence with one of these storms on its surface.