[X] My Assistant

[ElkGroveDan]

Dan, I think you've mistaken a part of sunlit soil in Phil's image as white stuff.

Agreed.

[ugordan]

Here's a flicker between sol 21 and 24 showing change (or, rather, lack of):


Ignore the color of the brightest part of the white stuff, it's overexposed. The small white chunk in sol 21 image appears to disappear in sol 24 (inset).

[silylene]

Not to toss out the water too soon, but ....

There is also the possibility that this loss of bright stuff in the trenches could be water of hydration evaporating from a salt newly exposed to the open dry atmosphere. (water of hydration of a salt is NOT ice.) This would change the crystal morphology of the salt. This would then be expected to change the brightness/reflectivity of the salts. Frankly, I am surprised to see that everyone is proclaiming this ice without eliminating this possibility.

For example, magnesium sulfate exists as MgSO4.7H2O. The waters of hydration are lost in a very dry atmosphere over about 3-4 days. The hydrated form is bright and crystalline and reflective. The annhydrous form is dull and non-reflective. I remember doing this experiment as a freshman in college!

I want to see analytical proof of water. I really do hope this is water !

p.s. I found this very nice paper, discussion exactly these phase transitions in mag sulfate under martian temperature/pressure conditions, and expected physical appearance: CONVERSION OF CRYSTALLINE MgSO4.XH2O TO THE HYDRATED AMORPHOUS PHASE – A
RAMAN, NIR, AND XRD STUDY. http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2168.pdf