Post #2by Spaceman Spiff » 27.09.2005, 08:41
Of course, the dark blotches are not holes, but dark dust gathered at the bottom of craters. The dust might have settled evenly at first (from Iapetus?) and then been shaken to the bottom after more shaking from further craters and impacts. There's also the streaks down the sides of craters and escarpments too. There's more evidence that dust gets shaken down on small bodies by impacts shaking the body: Eros, Phobos, Phoebe, Tempel 1, etc.
Compare to Don's moon Cima in his newly released Add On. In that, Don said the craters released a dark carbon-like substance from underneath the surface to create the dark spots, but here but here the craters have gathered dust into their pits from their sides.
You can also see that the face is mostly taken by a large, eroded impact crater. Most of the sides have collapsed into the pit, and forms a hump in the middle (the material tries to fit the local 'horizontal' which is not flat). It's since been pummelled by more craters. I think there's an even larger crater with a vague central peak on the other side.
Spiff.