Prometheus is an active volcano on Jupiter's moon Io. It is located on Io's hemisphere facing away from Jupiter at (1.52°S 153.94°W). Prometheus consists of a 28-kilometer (17 mi)-wide volcanic pit named Prometheus Patera and a 100-kilometer (62 mi)-long compound lava flow, all surrounded by reddish sulfur and circular, bright sulfur dioxide volcanic plume deposits.