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20 June 2008 @ 02:32 pm
ice on mars  
Via @MarsPhoenix, ice on Mars
(Deleted comment)
a very caring potato: broken icemollydot on June 20th, 2008 09:53 pm (UTC)
Good question. I had assumed water, but I hadn't thought of other types. It's not based on analysis (the sample in the oven now doesn't contain water), but on white stuff disappearing. The white stuff they have photographed was uncovered by either Phoenix landing or uncovering it later. They decided it was most likely either salt or ice. The disappearance would be from sublimation, which salt wouldn't do.
a very caring potatomollydot on June 20th, 2008 09:55 pm (UTC)
Ok, looking at MarsPhoenix's tweet again, I didn't just assume water ice - it says water. I don't know how they know.
a very caring potato: hitchhiker's wikimollydot on June 20th, 2008 09:59 pm (UTC)
Ah, according to wikipedia, Carbon dioxide has no liquid state at pressures below 5.1 atm, but is a solid at temperatures below -78 °C. I don't think Mars is cold enough to have kept it there for so long - the white patches would have disappeared sooner.
a very caring potato: broken icemollydot on June 23rd, 2008 10:39 am (UTC)

Temp too high and pressure too low for CO2 ice.
meehaneomeehaneo on June 20th, 2008 02:52 pm (UTC)
They said that the little silver pieces "disappeared" over time which seems to point to evaporation.

I'd love to think that there is one picture that they are not showing us which shows a little three fingered hand moving the blocks and a muffled snigger followed by "This'll drive the Earthlings mad!"
a very caring potato: orangemollydot on June 20th, 2008 09:54 pm (UTC)
Tee hee hee