AS17-2265(P)

Figure 147

 Click here for larger NASA image
 Click here for lunar chart showing location

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. - James W. Head III.