AS15-9866(P)

Figure 143

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High Sun views such as this often show fascinating dark and bright patterns that would be overwhelmed by highlights or shadows if the Sun were lower in the sky. This view of the 17-km-wide crater Jansen B shows numerous bright avalanche deposits on the steep crater walls, apparently originating at outcrop ledges near the top of the wall. Most avalanches stop in a moat at the base of the wall, but a few in the foreground extend out onto the irregular, inward- sloping floor. The floor is a jumble of slump blocks. Avalanching appears to be a major means of erosion on steep lunar slopes.    -K.A.H.