A couple of new color images were released today by the HiRISE team, including a looking at landslides along the Zunil crater rim and gas springs in the warming Southern Polar Cap. The Zunil view looks especially interesting (and I am not just saying that because my advisor has done a lot of work on that fresh impact crater). I think I will download that one.

Recent Landslide in Zunil Crater
PSP_001764_1880
http://hirise.lpl.arizona.edu/PSP_001764_1880

Spring Colors on the Southern Polar Cap on Mars
PSP_003734_0950
http://hirise.lpl.arizona.edu/PSP_003734_0950

Now that we have all experienced the new browser.....

...am I the only one here blown away by the dendritic patterns in Spring Colors on the Southern Polar Cap on Mars PSP_003734_0950 and the implications?

These are not something analagous to mud cracks. The continuous channels are evidence of flowing liquids, and the dearth of craters within implies recent and regular erosion. I can't imagine any other process. This is way cool.

Don't know that we can assume liquid activity - there is certainly some pretty dynamic fluid activity going on but the CO2 would either be freezing out or subliming and not going through a freeze\thaw cycle.

Even in mid SH summer the local temperature in these spots is below -100C so I don't think there is even the proverbial snowball's chance in hell that there could be liquid water involved.

Well that's why I am marvelling at these images. Those gullies just HAVE TO BE created by liquid (notice I didn't mention "water" above). I have no idea what liquid, but man those cracks are contiguous far longer than random chance would allow.

[quote name='ElkGroveDan' date='Jun 5 2007, 09:00 PM' post='91641']
Those gullies just HAVE TO BE created by liquid
/quote]

I don't see why. What's wrong with the erosion by trapped gas that they propose in the image caption? It's certainly an exotic process, but I'd say more believable than liquid in this context.

I guess I have a hard time picturing "trapped gas" flowing and eroding in a manner identical to that of a liquid. Call it geologic intuition.

I don't think that it's trapped gas so much as explosively sublimating gas - possibly leading to some sort of cascading\avalanche effect that then leads to these totally alien formations.

I think these channels only resemble dendritic channels in their forms. In fact, many of them define the boundaries of polygonally fractured dry-ice surficial plates, a patterning not normally noted in dendritic channel formation.

-the other Doug