File:Proclus crater hrp147.jpg

English: Oblique view of part of part of Proclus, on the moon. This is Figure 147 of Apollo Over the Moon (NASA SP-362, 1978), which has the following caption:
This oblique view looks south over the 26-km-diameter crater Proclus in the highlands at the western edge of Mare Crisium. Proclus is a young rayed crater that is distinctive because of the marked asymmetry of its ray system-a characteristic visible even in Earth-based telescopic views. The excluded zone is along the southwest edge (top of photograph) but is visible in this moderate Sun photo only as a slight albedo change. Laboratory experiments suggest that a low trajectory angle might account for the asymmetry. A number of large blocks can be seen at the edge of the crater rim. The exceptionally large block (arrow) is about 200 m wide and, judging from the length of the shadow it casts, nearly as high. As in several other craters shown in this chapter, a darker layer is present in the upper part of the crater wall.-J.W.H.