File:AS14-73-10142.jpg

English: Color image from lunar orbit. Interior (east wall) of Langrenus crater. North toward upper left.
This photo was used in Figure 18-2 of the Apollo 14 Preliminary Science Report (SP-272), which has the following caption:

East wall of Langrenus Crater. The color anomaly is located at point 1; bulbous domes on crater floor, at point 2; and typical slump blocks from crater walls, at point 3.

The text of the Report refers to the figure as follows:

A distinct color anomaly can be seen in photographs (AS14-73-10142 to 10148) of the eastern wall of Langrenus Crater. A distinct rusty color is evident in one of a group of smooth bulbous domes with single or multiple furrows at or near the crests (fig. 18-12). Except for the dome exhibiting the color anomaly, all have a light gray, faintly speckled appearance. These domes appear morphologically distinct from the sharper crested, more irregular hills that lie concentrically around the inner wall of Langrenus Crater and that are evidently slump blocks from the crater walls.

The rusty color in the domelike hill is evident in all seven of the cited photographs. A patch of dark material at the estimated location of this dome can be seen in Apollo photograph AS10-32-4676, thus confirming that the anomaly is not an artifact of the color photographs. The color anomaly may be of little regional geologic significance. However, in reference 18-13, it is pointed out that color differences on the lunar surface are attributable to gross differences in petrologic composition. The location of the dark material among a group of morphologically distinctive bulbous structures suggests that post-Langrenus endogenetic processes may be responsible for both the domes and the color anomaly.