The third closest satellite of Saturn, also known as Saturn XVI, orbiting at a distance of 139,350 km. It orbits Saturn in 0.613 days and acts as a shepherd moon to Saturn's F ring beyond it. It is irregularly shaped, 145 x 85 x 62 km. Prometheus was iscovered by S. Collins and others in 1980 from Voyager photos.
In Gk. mythology, Prometheus was a Titan who stole fire from Olympus and gave it to humankind, for which Zeus punished him horribly; son of Iapetus; brother of Atlas and Epimetheus. The name literally means "forethought," from from promethes "thinking before," from → pro- "before" + mathein "to learn," from enlargement of PIE base *men- "to think;" → idea for Pers. cognates.