Various sites are reporting on the recent pictures from Cassini-Huygens. It sent some images home that give some insight into the formation and history of Saturn’s moon Iapetus. The most remarkable feature of the moon is a ridge, a few miles high, that is visible on Iapetus’ forward hemisphere.
“Forward hemisphere? What are you talking about?” Well, like our own moon, Iapetus has one face that always points toward the planet. Thus Iapetus has one hemisphere that always faces into its own orbit, and it is on this hemisphere that most impacts occur (compare the number of squashed bugs on your front bumper to the number on your back bumper).
