Reference image
Object guide
Rhea is Saturn's second-largest moon (after Titan). Its surface is heavily cratered and may have faint rings or a tenuous atmosphere of oxygen and carbon dioxide. Rhea is approximately 1,527.6 km across.
How to observe Rhea
Rhea is resolved as a separate world mainly through imaging or spacecraft data; visually, its relationship to saturn is the key observing context.
Scientific context
Useful scale comparisons are 0.12 Earth diameters, 0.027 g surface gravity, 0.012 Earth years per orbit. These values are rounded from the catalogue measurements shown on this page.
- Radius
- 763.8 km
- Diameter
- 1,527.6 km
- Mass
- 2,306,500,000,000,000,000,000 kg
- Mean density
- 1.236 g/cm³
- Surface gravity
- 0.264 m/s² (0.027 g)
- Orbital period
- 4.518 days (0.012 years)
- Parent body
- saturn
0.12 Earth diameters0.027 g surface gravity0.012 Earth years per orbit
Source: NASA Science (checked 2026-08-09). Values are rounded catalogue measurements.
Interactive orbit model
Aug 13, 2026, 22:251×
Calculated positions / separate exploration scales