Rings are narrow, and contain concentrations of particles called ring arcs.
On its approach to Neptune in August 1989, Voyager 2 captured this image of the fourth and outermost of the giant gas planets. This image shows two of the four oval cloud features tracked by the cameras. The large dark oval near the left edge revolves around Neptune every 18 hours. The bright clouds immediately to the south and east of this oval substantially change their appearance in periods as short as 4 hours. The second dark spot, at lower right edge, revolves around Neptune every 16 hours.