Epimetheus
Moon· orbits Saturn
Epimetheus — moon of Saturn.
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Key facts
Mass
5.26 × 10¹⁷ kg
0.00000717 Moon masses
Radius
58.2 km
3% of our Moon's radius
Surface gravity
0.0104 m/s²
0% of Earth's gravity
Orbit around Saturn
16.8 hours
0.70 Earth days
Science
Physical
- Mass
- 5.26 × 10¹⁷ kg · 0.00000717 Moon masses
- JPL SSD Planetary Satellite Physical Parameters (GM SAT415) — dynamical (spacecraft ephemeris fit)
- Radius
- 58.2 km · 3% of our Moon's radius
- JPL SSD Planetary Satellite Physical Parameters (mean radius)
- Density
- 638 kg/m³ · 0.64× water
- Computed from mass and radius
- Surface gravity
- 0.0104 m/s² · 0% of Earth's gravity
- Computed from mass and radius
- Escape velocity
- 34.7 m/s · 0% of Earth's escape velocity
- Computed from mass and radius
Orbit around Saturn
- Distance from Saturn
- 151,400 km
- From JPL orbital elements
- Orbital period
- 16.80 hours
- From JPL orbital elements
- Eccentricity
- 0.02
- From JPL orbital elements
- Inclination to Saturn's Laplace plane
- 0.30 °
- From JPL orbital elements · The Laplace plane is the one a moon's orbit precesses about: close in it is the planet's equatorial plane, the plane of the rings, and further out it tilts toward the planet's own orbit.
Radiation & temperature
- Insolation
- 0.0112 S⊕ · 1% of the sunlight Earth receives
- Computed from the distance to the Sun (inverse-square; Earth's sunlight = 1), before any atmosphere.
Discovery & history
- By
- J. Fountain, S. Larson (1977), D. Cruikshank (1980)
Epimetheus was discovered in 1977, 1980 by J. Fountain and colleagues. Saturn's moons are named after the Titans, giants and monsters of Greek and Roman myth. Beyond its discovery and naming, little more about it has been individually recorded.
Images
Images from open archives · credit shown per image