Pele is an active volcano on the surface of Jupiter's moon Io. It is located on Io's trailing hemisphere at 18°42′S 255°18′W / 18.7°S 255.3°W / -18.7; -255.3.Coordinates: 18°42′S 255°18′W / 18.7°S 255.3°W / -18.7; -255.3. A large, 300-kilometer (190 mi) tall volcanic plume has been observed at Pele by various spacecraft starting with Voyager 1 in 1979, though it has not been persistent. The discovery of the Pele plume on March 8, 1979 confirmed the existence of active volcanism on Io. The plume is associated with a lava lake at the northern end of the mountain Danube Planum. Pele is also notable for a persistent, large red ring circling the volcano resulting from sulfurous fallout from the volcanic plume.