It’s Ice!

Posted by jns on June 19, 2008

This news from NASA and the Phoenix Mars Lander seems to be traveling around with near light speed:

Bright Chunks at Phoenix Lander’s Mars Site Must Have Been Ice 06.19.08

TUCSON, Ariz. – Dice-size crumbs of bright material have vanished from inside a trench where they were photographed by NASA’s Phoenix Mars Lander four days ago, convincing scientists that the material was frozen water that vaporized after digging exposed it.

“It must be ice,” said Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson. “These little clumps completely disappearing over the course of a few days, that is perfect evidence that it’s ice. There had been some question whether the bright material was salt. Salt can’t do that.”

The chunks were left at the bottom of a trench informally called “Dodo-Goldilocks” when Phoenix’s Robotic Arm enlarged that trench on June 15, during the 20th Martian day, or sol, since landing. Several were gone when Phoenix looked at the trench early today, on Sol 24.

[more]

Of course this is big news for the mission and everyone watching it. Finding evidence of water^* on Mars–even evidence of water ever having been on Mars–is usually taken as a necessary condition for finding evidence of any life existing, or having existed at one time, on Mars. Whether this is really true is another matter, but water played a necessary role for life to appear on Earth so it’s thought that no water would mean no chance of life.

Now we believe that there is currently frozen water, existing now, today, on Mars. It doesn’t mean extraterrestrial life but a serious road-block (i.e., no water) has been removed. Besides, discovering signs of water, either now or ever, has been a long, long quest for a good number of people, and now they’ve found it.

A lot of people are pretty excited.
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^* The evidence: four days ago Phoenix was digging a trench when it came upon a solid, white layer. The layer could have been frozen water or maybe something like salt. What’s happened in the last four days? Some small chunks of the white substance, loosened when Phoenix was digging, disappeared. Disappearing means evaporating (more precisely, “sublimating”, which is the word that means evaporating directly from the solid form without first melting), something that salt and other likely substances would emphatically not do, whereas exposed water ice would do exactly that.