Dividing Mare Imbrium from Mare Serenitatis, is the triangular mass of peaks, the Montes Caucasus, my favorites of all the lunar mountains, running down the middle of this image. On the left side of this image we see two large craters still in shadow, Aristillus (56km dia.) above and Autolycus (41km) below. Note the splash pattern of the ejecta about the larger crater and the tighter crosshatch pattern around Autolycus. To the right (east) of Aristillus up against the Montes Caucasus, is a mild swelling that is the dome Ari1 about 54x35km in area and 85m (±10m) high. Rima Thaetetus can be seen on the eastern side of this dome. Then east of Autolycus is a large low circular swelling that is another dome, Au1 some 28km diameter (±0.5m) and only 75m (±10m) in height.
A small piece of the great crater Archimedes (85 km) can be seen in the lower left corner. In the upper left is the bright Mon Piton rising abruptly 2250m above the surrounding plain of Mare Imbrium. What a sight that must be! Just right of that rampart is the very identifiable crater Cassini with Cassini A (15km) and the smaller Cassini B (9km) contained within its low walls. The ejecta blanket surrounding this crater is best seen on the right (east) side. Below Cassini is the odd shaped crater Thaetetus (24km) and in the north of the Caucasus is another non-round crater Calippus (32km). These two craters point north to a “U” shaped feature that is Alexander (85km). Some references list this at 95km but it’s hard to see a circular feature here at all!
