Epimetheus

Saturn XI

Epimetheus Facts

• Epimetheus is the fifth of Saturn's known satellites:
  • distance from Saturn: 151,422 km
  • diameter: 115 km (144 x 108 x 98)
  • mass: 5.6e17 kg
  a.k.a. 1980 S 3

• Pronounced "ep eh MEE thee us"

• Epimetheus was the son of Iapetus and brother of Prometheus and Atlas; husband of Pandora. "Epimetheus" is Greek for "hindsight".

• Discovered by Walker, Larson, and Fountain in 1978 and confirmed in 1980 by Voyager 1. It was probably also observed by both Walker and Dollfus in 1966 when they discovered Janus.

• Epimetheus and Janus are "co-orbital".

• There are several craters larger than 30 km in diameter as well as both large and small ridges and grooves. The extensive cratering indicates the Epimetheus must be quite old.

• The dark line across the surface in the image above is actually the shadow of the Saturn's F-ring.

Pictures

1. (above) Epimetheus 43k gif
2. Epimetheus, moon of Saturn 127k gif
3. Map of Epimetheus 99k gif
4. several moons (HST) 90k jpg; 215k gif (caption)

More about Epimetheus

• from LANL

Open Issues

• Little is known about Epimetheus.
• Is the co-orbital relationship with Janus stable?