Is it ice, or salt?
From the International Herald Tribune:
Shallow trenches excavated by the lander's backhoe-like robotic arm have
turned up specks and at times even stripes of mysterious white material mixed in
with the clumpy, reddish dirt.
New photos showed the exposed bright substance present only in the top
part of the trench, suggesting it's not uniform throughout the excavation site.
Phoenix will take images of the trench dubbed "Dodo-Goldilocks" over the next
few days to record any changes.
If it's ice, scientists expect it to sublimate — or go from solid to gas,
bypassing the liquid stage — when exposed to the sun because of the planet's
frigid temperatures and low atmospheric pressure.
Even if it's not ice, the discovery of salt would also be significant because it's normally formed when water evaporates in the soil.
I say, it's cocaine. How else are the martians going to stay up through those long Martian nights?