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Neptune's Atmosphere



Clouds of Blue

Neptune's atmosphere is made up of hydrogen, helium, and methane. Like Earth's atmosphere, Neptune's has clouds and storm systems that revolve around the planet, but with wind speeds of 300 m/sec (700 mi/hr), and clouds of frozen methane.

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NASA Press Release #P34648
The "Great Dark Spot" discovered by Voyager 2 is a storm system that resembles Jupiter's Red Spot, and is surrounded by white cirrus clouds of frozen methane.

 

Changes In Cloud Structure

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NASA Press Release #P34610

These images of the Great Dark Spot were taken by Voyager 2 over a 4 1/2 day period at intervals of 18 hours. As shown on the left, a "tail" of the dark spot separated into individual spots that moved westward. The Great Dark Spot may have an overall counterclockwise rotation as suggested by the lighter toned clouds surrounding the main spot.

 

 


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