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Posted by: Sunspot Jun 5 2009, 11:24 AM

More great views of Mars from Mars Express

http://www.esa.int/esaSC/SEMSKCVTGVF_index_0.html

"The High Resolution Stereo Camera on ESA’s Mars Express orbiter has obtained images of Hephaestus Fossae, a region on Mars dotted with craters and channel systems."

Posted by: Juramike Jun 5 2009, 01:38 PM

Very very cool!

There's some really neat stuff going in in the upper right where it looks like the fluid flowed along, punched through into a crack and just soaked into the surface! (Note where the channel hits a crack and the walls are no longer evident on what should have been the downstream side of the gap.)

BTW, the tapered forms on the left side of the crater seem to indicate that the surface flow was running left to right (downgradient) before the impact, and that the impact just got lucky and smacked into the middle of the channel.

I think the main channel existed before the impact. (But the impact generated another round of fluid stuff as seen in the debris apron)

I really love this image.

Here's my take on what could be going on:


(And yes, past surface flow on a sediment-covered glacier seems like a possibility)

Posted by: Pavel Jun 5 2009, 04:00 PM

That's quite a splat! The crater looks similar to Iazu crater south of Endeavor and to many craters in the northern plains. Can it be that those craters were produced by impactors hitting wet soil? I guess either there is much more ejecta in such events (perhaps due to less friction), or the wet ejecta is cemented and survives erosion better than dry ejecta.