[meteorite-list] Success! The Phoenix has landed safely.

From: Darren Garrison <cynapse_at_meteoritecentral.com>
Date: Mon, 26 May 2008 18:28:19 -0400
Message-ID: <f9em3454cfamlvupp05p4c6ork7c71dsj9_at_4ax.com>

On Mon, 26 May 2008 16:37:47 -0500, you wrote:

>pop out a little more detail. Darren Garrison has donated
>some webspace to post my processed image to:
>http://webpages.charter.net/garrison6328/tmp/First_Pictures_Bright.Cont.Unscharf_lg313_phoenix.jpg
>

Below are the comments I made to Sterling off-list about this (when I offered
the web space):

Might the "scratches" be seeing the polygonal "cracked mud" features at a low
angle? Possibly with low-angle sunlight contributing shadows to it? The sizes
of the rocks is interesting, in that they are all so similar, and all (as far as
I can tell) mostly on the small side. When I first saw the first couple of
images, I thought "more blueberries", as they were so small and often rounded.
But too many larger, angular fragments to all be blueberries like seen elsewhere
on Mars.

If they were from a glacier, I'd think random sizes. From a big flood, a little
less random but still largely sorted. From a river, highly sorted. From
impacts (since it would likely be overlapping debris feilds from multiple
impacts) I'd expect random sizes. So of those choices, I'd rule out everything
but a river bed. But I have another idea-- weathering through many freeze-thaw
cycles (with H2O and CO2 ice filling the cracks) breaking down big rocks into
small rocks. That, and the effect of freezing in soil pushing rocks up to the
surface-- I'd think that there could be some size sorting in that process, if it
were involved.

http://findarticles.com/p/articles/mi_m1200/is_n26-27_v136/ai_8242911
Received on Mon 26 May 2008 06:28:19 PM PDT