Mars
With a passion for geology and space exploration, I, like many others these days keep a eye out on everything related to the Phoenix lander. These are exciting days. Got nothing to say that other bloggers havent already said. Except one question perhaps - can smaller rocks become smoothly rounded like the those seen on this link without water? Can a wind (and temperature, and chemical…) based erosion accomplish that?
May 26, 2008 + Posted in Soil, Planetary studies +
Answering your question: I think that aeolion processes on their own could round these rocks like they are. What would be really interesting is a big close-up on those rocks to see their surface details. Sand-blasting them would result in round but rough surfaces whereas water would make smooth surfaces and ice (glaciers) would scratch their surfaces and give characteristic marks. All of these of course greatly generalised without getting into details.
Comment by Lost Geologist — May 26, 2008 @ 6:36 pm
Looking at some of the fotos on the lander website I actually think these pebbles are not as rounded as it may first appear. They seem to be quite angular with only rounded edges that remind me of ventifacts.
Comment by Lost Geologist — May 26, 2008 @ 6:47 pm
Lost Geologist: I see, thanks for your answer.
Comment by Antimonite — May 26, 2008 @ 7:22 pm
The most striking feature of these pictures is something looking like what would be called “polygon soils” i.e soil showing slightly convex geometric forms, with small particules accumulated beteween the ridges. It is beleived to be a periglacial process on earth.
Here is a picture from the Alps:
http://paysagesglaciaires.net/site_source/Photos/DX1.jpg
Here is a picture from Phoenix:
http://fawkes4.lpl.arizona.edu/images.php?gID=437&cID=8
Comment by Valentin — May 27, 2008 @ 6:55 am
Valentin: Yes, striking resemblance.
Comment by Antimonite — May 27, 2008 @ 5:39 pm