image by Paolo R. Lazzarotti, Massa, Italy.
This is a mysterious image. Its dark with dozens of small to medium sized craters, lots of lineations and a couple of odd knobs - do you see them? First, the area. At upper right with a dot of brightness for its central peak is Pitiscus, with Hommel just below. At bottom left is Manzinus, and Mutus is full of shadow above it. Many of the 20-30 km wide craters are thought to be secondary craters, from Orientale or someplace else? But there is a smaller scale of possible secondaries that are also of uncertain origin. In the left-center part of the image there are alignments of small craters and a strange linear depression from Jacobi A to Tannerus (for those without a Rükl click here). If these are secondary features related to a younger impact it could be Rutherfurd on the south wall of Clavius. But there is a larger feature here, supposedly, that may play a role. There are two rounded knobs, just west of Mutus and a bigger one right on the left margin. On the Moon the main process that makes topography is impact, and these knobs and a few other similar features were interpreted by Don Wilhelms and Farouk El Baz as the remnant rim of the ancient Mutus-Vlacq impact basin. Most of the terrain visible is inside the basin whose reality was surprisingly confirmed by Clementine altimetry which showed a depression 3 km deep!
1 October 2007, 4:08 UT. Gladius CF-315 Lazzarotti telescope (f/25), LVI 1392 PRO experimental camera, Edmund Optics R filter, 160 frames stacked out of 2000.
Rükl plates 74 & 75
Yesterday's LPOD: Lunar Classics
Tomorrow's LPOD: Wahoo for Wan-Hoo