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[ElkGroveDan]

Successful touchdown

[Bill Harris]

I dunno. I mentioned mine dumps on another thread, and they sure look like this in Butte, MT: no coherent pattern in rock shapes, lots of deposition of same on or near frost heave lines (it gets VERY cold there in the winter, and unexpectedly warm in the summer). I'd say that a lot of the rocks we see are being excavated by frost heaves over time.

I'd guess that we're seeing frost heave, plus wind deflation, plus ejecta from the crater to the east. Some pebbles look angular and some rounded. The frost polygons are reminescent of parts of Meridiani, no? Different origin, similar erosional processes.

--Bill

[imipak]

The frost polygons are reminescent of parts of Meridiani, no? Different origin, similar erosional processes.

It does look reminiscent of the etched terrain, but I think the scales are different. This is flatter than Meridiani, and the vertical relief of each polygon looks pretty invariant. So what appears to be a sea of dune crests are really the darker sides of the polygons. My estimate last night of 30-50cm height looks to be a 10x over-estimate in the cold light of, er, early afternoon. I can't wait for anaglyphs showing the arm out, to provide scale. As to erosional processes - no, I don't think there's CO2 frost cracking / exfoliation at Meridiani, just aeolian erosion caused by slow moving airborne fines and saltation.

The darker fine material along the edges of the polygons where they slope downwards towards the "cracks", has a crust-like appearance in places. Presumably that's fine dust eroded from the pebbles, and it's preferentially sorted onto the sides of the "valleys" by wind (?)

I have to say I'm quite happy Teshiener won't have to make route maps by deciphering which nearly identical dune we're parked next to today... that whole slog down to Erebus and Beagle was purgatory to me