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Encyclopedia > Saturn > Satellites > Iapetus
IAPETUS : SATELLITE VIII OF SATURN
Iapetus (Saturn VIII)was discovered by Cassini in 1671. Its revolution period is 79 days and 8 hours.
Iapetus has a very dark and very clear other hemisphere. This is the leading side of the satellite, as Tethys is darker.
| Characteristics | Values |
|---|---|
| Semi-major axis in km | 3 561 850 |
| Revolution period | 79.331 days |
| Rotation period | 79.331 days |
| Orbital velocity | 3 km/s |
| Inclination on the equator of Saturn | 18.5° |
| Eccentricity of the orbit | 0.0283 |
| Equatorial diameter (Earth=1) | 0.11 |
| Equatorial diameter | 1436 km |
| Visual magnitude at the opposition | 10.2 / 11.9 |
| Flattening | 0 |
| Mass (Saturn=1) | 2.8/1000 000 |
| Density (water=1) | 1.3 |
| Escape velocity | 586 m/s |
| Reflectivity (geometric albedo) | 0.5 / 0.1 |
| The highest peak | 12 000m |
| Deepest pit | ? |
| Atmosphere | no |
| Composition | ice majority silicates |