THE GREAT DARK SPOT:
       Neptune has one storm system know as the Great Dark Spot. The storm system is thought to be rotating counter clockwise due to a spiral shape of both the dark boundary and the white cirrus surrounding the spot. Recent observations made with the Hubble Space Telescope indicate that the Great Dark Spot actually no longer exists. But, a second "great dark spot" has been observed in the northern hemisphere of Neptune. Because Neptune radiates twice as much energy as it receives from the dim and distant sun, the mechanism that drives its weather systems must be very different from that of Earth. An internal heat source may exist that warms the cloud tops from below. Slight changes in the temperature differential from cloud bottom to top might trigger rapid, large-scale changes in atmospheric circulation.

The old "Great Dark Spot" and it's curious sled-like spot taken in August 1989 by the Voyager 2.

The Hubble Space Telescope took these pictures of Neptune (with a filter), in June 1994, and found that the spot had disapeared! The one on the left is one side of Neptune and  the one on the right is of the exact opposite side, about 9 hours later.

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RINGS:
       Neptune has a set of four rings which are very narrow and faint. They are made up of dust particles made by tiny meteorites that have crashed into Neptune's moons. The rings appear to be arcs from ground based observations but the Voyager 2 revealed that the arcs turned were bright spots or clumps in the ring system. The exact cause of these bright clumps is unknown.
       The ring system was found to contain several faint rings, the outermost of which, Adams, contains three prominent arcs now named Liberty, Equality and Fraternity. Several other rings were detected as well. In addition to the Adams Ring which is 63,000 kilometer from the center of Neptune, the Leverrier Ring is at 53,000 km and the broader, fainter Galle Ring is at 42,000 km. A faint outward extension to the Leverrier Ring has been named Lassell and is bounded at its outer edge by the Arago Ring at 57,000 km.

The Voyager 2 snapped this picture with its wide angle camera on Aug. 26, 1989. The rings can be clearly seen. The black bar in the middle is the removal of the over exposure to Neptune's crescent, from the picture.

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