Sunday, 3 August 2008

Is it ice? Part 3 - Yes!

Water on Mars:
Photo credit : Rob @ Bayblab

OK, I've dithered about this. Pull up your trousers here and here.

Not that I ever really doubted that ice was present on Mars. The polar caps have been known to be composed of water ice(15%) and frozen carbon dioxide (CO2 - dry ice - 85%) from a long time back.

But you want that final cherry. The tension has been well, tense; with oven doors failing to open correctly, fears of a short circuit and claggy Marsdust but finally the robot arm has delivered a (small) scoopful of the solid stuff to a properly working TEGA slot. Photo credit: NASA

This instrument gently warms up the sample and measures the molecular/atomic weight of the gases which evaporates off. Guess what, at 32°F (0°C for the non-Americans) a phase change was observed - that's something melting. In the evolved gases, a signal with a mass of 18 was detected!

H - Hydrogen : atomic weight = 1
O - Oxygen : atomic weight = 16
H2O - Water : molecular weight = 1+1+16 = 18

What were you expecting, some alloy of Lithium and Boron?
Dihydro quodrahelium (He4H2)? Nah, look it up. That was water. I am convinced, but what I want to know now is did they see any deuterium 2H or any 18O. These are heavy isotopes of hydrogen and oxygen and the isotope ratios can provide a lot of information on how the ice may have formed.

In the same press release from NASA a five week extension to the Phoenix mission was announced. This will keep data coming back until early November rather than stopping at the end of August. After that the Martian winter will be setting in, light levels will fall and the solar panels will cease to work. Phoenix will freeze :(
Update: Emily Lakdawalla notes the sample was too small to observe a deuterium to hydrogen ratio. Oh well, better luck next time.

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