Still working on an Phoenix has been digging shallow trenches on Mars, and hitting hard stuff, which is bright white - like maybe ice.
Now bits of the stuff are vanishing before our eyes...
The scoop had dislodged some ~ 1cm chunks of the white stuff which were displaced to the end of the trench.
These have now vanished.
Like sublimated.
So, probably not salt deposits, we think...
Given the ambient temperature, exposed water ice looks like a good bet.
For real. - Might worry it is dry ice, but it seems too warm for there to be dry ice there, and also it is not so hard - I'm assuming Phoenix has quantitative measurements of the hardness, of course.
Now they need to actually pick up some of these chunks, before they sublimate, and get some chips of them, somehow, into the little ovens, and bake them out - see what comes out.
Also looks like the exposed hard patch to the upper right is shrinking, presumably also through sublimation.
Er, better be more underneath there... be embarrassing if it was ice, and that was all of it, eh?
Physical Science
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I think it's Martian street cleaners sweeping the stuff up between frames.
Actually, this is one of the most insanely cool things I've seen in a long while.
Posted by: csrster | June 20, 2008 6:00 AM
Dry Ice was the first thing that came to my mind, but they would have looked pretty foolish not to have ruled that out. Haven't seen any mention of solid CO2 in anything published so far. I assume they have a way to measure the soil temperature.
Posted by: S. C. Hartman | June 20, 2008 6:37 AM
I'm a bit confused by this. They found ice, near the giant polar ice cap, right? So is this not exactly what we would expect?
I'm happy for the detection, but I'm just not sure if this falls into the "this is new" or the "this is what we expected" category of discoveries.
Posted by: Colin | June 20, 2008 9:30 AM
I think this is one of the "what we really hoped for" things.
Yes, the "old persistent ice" at the pole is probably water, and yes, the orbital evidence suggested strongly there was subareal water ice there - but to actually have it right under the lander and shallow and accessible is beyond "what we would expect" into "phew it really is there like we hoped it might be" - so not completely new, per se, more a step along the optimal path for discovery.
Or, you could think of it as confirmation that the science team chose well when picking a landing site and an approach to access any water ice deposits.
Posted by: Steinn Sigurdsson | June 20, 2008 11:05 AM
Very cool - but do mention it is the 'chunky' stuff on the bottom left of the trench that we should concentrate on (inside the shaded area), not the white stuff at the top...
Posted by: changcho | June 20, 2008 4:25 PM