Prometheus acts as a shepherding satellite, constraining the extent of the inner edge of Saturn's F Ring. Prometheus is extremely irregular and has visible craters -- some up to 20 km (12.4 miles) in diameter. However, it is much less cratered than its nearby neighbors Pandora, Janus and Epimetheus. The density of Prometheus has been estimated to be low; it is probably a porous, icy body.
The potato-shaped moon is about 86 km (53 miles) across.
Discovery:
The Voyager 1 science team discovered Prometheus in October 1980.
How Prometheus Got its Name:
Moons of Saturn were originally named for Greco-Roman Titans and descendants of the Titans. But as many new moons were discovered scientists began selecting names from more mythologies, including Gallic, Inuit and Norse stories.
Prometheus [pro-MEE-thee-us] was the son of the Titan Iapetus and brother of Atlas and Epimetheus. He is best known in Greek mythology for stealing fire from the gods and giving it to humanity.
Prometheus was originally designated S/1980 S27.
