re: Galle Crater Scene
Very interesting picture, Steve, thanks!
Those dust devils are recent and keep appearing here and there, on Mars. They must somehow also shape the Mars landscape, especially if we consider billions of years. I wonder if those gullies are much older than the dust devils.
And knowing that water cannot be liquid, certainly for the past billion years, and those gullies can't be that old, so what process is involved is an interesting question.
Raoul