Neptune's Great Dark Spot Gone But Not Forgotten

Neptune's Great Dark Spot Gone But Not Forgotten



When NASA's Voyager 2 spacecraft flew bydistant Neptune in August of 1989 astronomerswere shocked.Since Neptune receives only 3 percentthe sunlight Jupiter does, theyexpected to find a dormant, dark, frigid planet.Instead, the Voyager images revealedevidence of a dynamic and turbulent world.One of the most spectacular discoveries was of the Great Dark Spot, shown here in close-up.Surprisingly, it wascomparable in size and at the same relative southern latitude as Jupiter'sGreat Red Spot, appearing to be asimilar rotating storm system.Winds near the spot were measured up to1500 miles per hour, the strongest recorded on any planet.The Voyager data also revealed that the GreatDark Spot varied significantly in size during the brief flyby.When the HubbleSpace Telescope viewed the planet in 1994, the spot hadvanished -- only to be replaced by another darkspot in the planet's northern hemisphere!