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Dione

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MOON

Dione

Icy moon with striking bright "wispy" ice cliffs and a possible subsurface ocean.

Orbits Saturn

Physical Properties

561 km
1.0954868e21 kg
1.478 g/cm³
0.232 m/s²
65.7 h
0.998
87 K

Orbit

Saturn
377,396 km
0.0022
0.019°
2.737 d

Sources & Further Reading

Numerical values (radius, mass, orbital elements, temperatures) are drawn from NASA NSSDC Planetary Fact Sheets, JPL Horizons, and the JPL Small-Body Database. Last refreshed: 2026-04-18 18:19:24.

Dione is Saturn’s fourth-largest moon, with a rocky core and icy mantle. Its trailing hemisphere displays striking bright, streaky “wispy terrain” — originally a mystery, but revealed by Cassini to be networks of bright ice cliffs hundreds of meters tall. Dione is in a 2:1 orbital resonance with Enceladus, which may contribute to tidal heating. Cassini gravity data hint at a subsurface ocean beneath ~100 km of ice.