Why is this crater so bouldered? Bouldery craters are primarily the result of bolides impacting solid material. More cohesive materials produce larger boulders when they are impacted. Craters like these can give clues as to the thickness of the regolith. As craters increase in diameter, they excavate further into the surface. So if a crater has no boulders, it has probably excavated only regolith. This impact though has punched through the overlying regolith and fragmented the underlying mare basalt into large boulders.
Can you find the transition between unbouldered and bouldery craters in the full LROC NAC!
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