Great Dark Spot | Article about Great Dark Spot by The Free Dictionary
Great Dark Spot
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Great Dark Spot A prominent feature in Neptune's atmosphere, similar in many ways to Jupiter's Great Red Spot. The Great Dark Spot measures roughly 12 000 km by 8000 km and, scaled down by the same factor that Neptune's diameter is smaller than Jupiter's, occupies a similar proportion of surface area to that occupied by the Great Red Spot. The Great Dark Spot is a high-pressure system around which winds flow in a counterclockwise direction. Wind speeds around the Great Dark Spot are near supersonic at about 700 m s–1.