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Here is how Hadley Rille first appeared to the Apollo 15 astronauts in the LM. They landed in the right foreground. The large subdued crater in the foreground, St. George, is on a mountain to which astronauts drove. Hadley Rille is mainly in the mare basalts of Palus Putredinus. The rille cuts against older mountains in the foreground and at the upper right. Along the top (north) of this photo the rille is discontinuous and is similar in many respects to a partly collapsed lava tube, although it is much bigger than any terrestrial counterpart. The rille is 1.5 km wide and over 300 m deep. It is thought to be a giant conduit that carried lava from an eruptive vent far south of this scene. Topographic information obtained from the Apollo 15 photographs supports this possibility; however, many puzzles about the rille remain. - Keith A. Howard.
Report Source: NASA SP-362, Page 195, Figure 204
This web page was created by Francis Ridge
for The Lunascan Project