Aster › Space program › Rhea
Rhea
Position on the route: 19/45 · level needed 125 · journey (Mk0 engine) 24.6 h
By the numbers
| Diameter | 1,527 km |
|---|---|
| Gravity | 0.264 m/s² |
| Albedo | 70 % |
| Atmosphere | a thin O₂ and CO₂ exosphere |
The story
Saturn’s second-largest moon: a mix of ice and rock, heavily cratered. Cassini (2010) measured a very thin oxygen and carbon-dioxide exosphere: Saturn’s radiation belt is breaking up the ice.
The surface is full of dark ‘ice cliffs’ and bright craters; a claim in 2008 that Rhea might have a ring system was later not confirmed.
Missions
- Pioneer 11 and Voyager: the first images
- Cassini (2005–2017): close flybys
Colony note
Plenty of ice, no shield needed; a logistics base for the Saturn system.
What probes bring back
- Saturn’s second-largest moon; a thin oxygen and carbon-dioxide exosphere has been measured.
- Albedo 70 %: a clean water-ice surface.