Moon of Saturn
Diameter: 1436 km
Distance: 3560800 km (mean)
Period: 79.331 days
Eccentricity: 0.028
Inclination: 7.57°
Magnitude: 11

Discovered in 1671, Iapetus is dark as coal on its leading hemisphere and bright on its trailing caused by a mechanism which is still unknown, probably thermal segregation. The second most notable feature of Iapetus is its equatorial ridge, a chain of 10km high mountains girdling the moon's equator.