Interesting article. Are we to assume the composition of the Martian cloud is water vapor? I'm not sure that the existence of water in Mars has been established with absolute certainty.
That cloud is not water vapor. Nearly all of the atmosphere of Mars is carbon dioxide, which as we know can freeze into “dry ice”. And when dry ice melts, it rapidly becomes a gas, which is the fuel behind the smoke machines used on stages and concerts.
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@Deus Ex Machina
Yes, Mars has polar ice caps and small amounts of atmospheric water.
@Marshall - the smoke you see from dry ice is actually condensed water vapour. Gaseous carbon dioxide is entirely transparent.
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