Neptune's rings Four dark planetary rings around Neptune, discovered in 1976 during close observation of an occultation of a star by Neptune and confirmed during the Voyager 2 flyby in 1989 (see table). The Adams and Le Verrier rings are quite thin. The Adams ring has several brighter arcs of material, first observed from Earth. Two broad rings, Galle and Plateau, are diffuse sheets of fine particles. The Plateau has a brighter edge at a distance of about 57 500 km from the planet.