Intricate gullies have formed on the northern wall of this impact crater located in the Terra Cimmeria region.
This crater may have formed in a region rich in ground water. This ground water likely flowed down the wall, eventually eroding numerous gullies while carrying sediments to form fan deposits. Ultimately the water likely infiltrated and froze beneath the surface. Other hypotheses say gullies form through carbon dioxide frost avalanches that we can see today.
What about this chain of pits snaking their way downhill? After material was transported, subsurface voids may have formed, removing support for the… [More at link]