There are some features on the moon that we are drawn to and will go to great lengths to get a good look at them. The “crater” Lamont is one of these. I put the word “crater” in quotes because it is not a crater in the sense that we normally think of them. This was a crater of some 70-80 km diameter, before the flooding of Tranquillitatis and can be seen just left of center in this image. Note the wonderful radial ridges stretching across the mare especially to north and south. These ridges are not very high, possibly only a hundred feed or so, thus they can best be seen at low sun angles like this image. Three similar sized craters that frame Lamont. On the terminator above Lamont is Arago (27km dia.) and below that is Sabine (31km). Then right of center is Maskelyne (26km). Below Arago is a smaller crater, Manners (15km). Roughly halfway between Maskelyne and Manners is the impact site for Ranger 8, the second successful Ranger probe in the series, sent to get close up images of possible manned lunar landing sites. It impacted on Feb. 20, 1965. The unsuccessful Ranger 6 impacted almost directly in-between Arago and Sabine almost exactly a year earlier. A little over two years after the Ranger 8 mission, on Sept. 11, 1967 Surveyor 5 landed south of that area about one third of the way from Sabine to Maskelyne. Just under two more years later Apollo 11 landed just south of the Surveyor site, on July 20, 1969. Here that spot is located in the flat area between ridges just north of the small crater Moltke (6km) on the north side of the graben-like Rimae Hypatia at the bottom.
Getting back to Lamont, this shadow or ghost crater has an outer ring that can be seen in this image about 135km across. Beneath this is a mascon (mass concentration) about this same size discovered by a Lunar Orbiter spacecraft. This mascon is thought to be evidence that Lamont is a buried impact basin that was covered by the Tranquillitatis lavas, a situation similar to Grimaldi.
Notice that Lamont sits in a brighter area of the Tranquillitatis floor. This is most obvious north and east of the crater. The boundary of this region runs right over the wrinkle ridges as if they were not there! This is thought to be caused from a high density of tiny craters with bright rims and indeed you can see this in the LROC QuickMap images.
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One last item, in the upper right corner of this image you can see a small dome. I can find no identification for it but on the LROC images it shows a pit very near the summit. I’m sure a thorough examination of this image would turn up more such domes.
