heating and cooling as a cause of boulder falls?
Thanks LJK - that's a great link.
I'm curious whether expansion and contraction of surface rock as it heats and cools might not be a cause of the boulders breaking off, on both Mars and the Moon. Neither the Moon nor the Mars captions mention that possibility. While rock wouldn't expand and contract much, going through millions (billions?) of daily cycles might have an effect.
I'm not talking about freeze-thaw effects (just the expansion of the rock itself), although maybe freeze-thaw does play some role for water a centimeter or two inside below the surface of Mars rocks.