Thanks for that explanation, Mark. Good to hear from you! I seem to recall a similar canyon in northern Arizona or southern Utah; unreal swirls unlike anything else I've ever seen. I have heard that the canyon is kept secret and only a few people are permitted to hike into it every year. Called "The Wave" or something similar. Ring a bell? I doubt that the Martian features are sandstone, but the morphology is certainly similar. Do you think there are parallels here? C. --- Mark Dakins <mdakins@earthlink.net> wrote:

Oh, he's still lurking around somewhere. Still available for an opinion, for a suitable price of course ;-)

There actually are quite a few pictures similar to this that have come back from several different areas on Mars.

I attended the annual Mars Society conference last August and there was quite a bit of discussion of places like this. There are quite a few different suggestions.

I think that the most common one is that this is differential weathering (probably mostly from wind erosion but maybe also at least some frost and maybe even water caused) due to differing hardness in the underlying layer(s). That of course begs the question of what this/these layer(s) are and how they came to look like a swirl cake. Here correspondent sayth not. This could be tough ground to get a rover onto/across. Really detailed hyperspectral imaging and/or other sophisticated remote sensing technologies might tell us what this stuff is and how it got this way or it might not. We may not know until a good field geologist with a rock hammer in his hand can walk across it and sample and analyze it.

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