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The Spot's of Neptune
The Great Dark Spot (GDS) is one of the most prominent features of Neptune's surface. In contrast to the Great Red Spot on Jupiter, the GDS is very dark and about a third the size (it can fit about one Earth inside). The GDS moves across the surface of Neptune rather quickly, about 300 meters/second (700 miles per hour) westward and the winds around the GDS is clocked to be the fastest in the solar system: 2,000 kilometers an hour (1,200 miles per hour). From evidence gathered from images, it seems that the GDS rotates in a counterclockwise motion, as seen from the pinwheel patterns that arise in the storm.
In 1994, imaging confirmed that the GDS has vanished! Either the hurricane-like storm dissipated due to the extremely dynamic weather conditions on the planet or it is being shielded from site by other clouds on the surface. Also found missing was the Small Dark Spot imaged by Voyager in 1989 that once existed in the southern hemisphere. The cause for the dynamic weather conditions on Neptune is probably due to the differing temperatures between the top and bottom of the clouds. In turn, a New Dark Spot has formed, discovered by the Hubble Space Telescope in June 1994.
The New Dark Spot is a new spot that was discovered by the Hubble Space Telescope after it had found that the Great Dark Spot and Small Dark Spot had disappeared in 1994. The New Dark Spot was much like its predecessor, having the same high altitude clouds and dark complexion. The gasses in this storm are high up due to the force of surface pressure, in which the gasses freeze to become methane ice. The dark area seen could be a swirling region of transparent gas that acts as a window to a lower area in Neptune.
Because of Neptune's harsh weather conditions, it could be before long that the New Dark Spot dissapates only to have an even newer storm takes its place…
In addition to find the Great Dark Spot, Voyager 2 found an irregular shaped cloud that flies eastward around the circumference of Neptune every sixteen hours or so. It has been named the Scooter for this reason and is probably a plume rising from somewhere lower in the atmosphere.
When Voyager 2 found the Great Dark Spot, it discovered a similar structure much smaller, now dubbed as the Small Dark Spot. It was south of the Great Dark Spot and is probably a storm in the atmosphere. It was found missing on June 1994 when the Hubble Space Telescope imaged Neptune.
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