Mike Wall, Space.com (January 6, 2011)
"NASA's Viking landers may have detected the ingredients for life on Mars after all, according to a new study.
"Back in the 1970s, the two Viking probes scooped up and heated Martian dirt, then looked for organic molecules — the carbon-based building blocks of life as we know it - in the samples. The landers found little, aside from two strange chlorine compounds that researchers at the time attributed to contamination from cleaning fluids.
"But the new study suggests that the soil did indeed contain organics, which can have biological or nonbiological origins. They were just destroyed before Viking could detect them.
" 'This result is saying that there are organic molecules on Mars,' study co-author Chris McKay, of NASA's Ames Research Center in Moffett Field, Calif., told SPACE.com. 'It doesn't say anything about life now, or life in the past. But it does open up the possibility of searching for organic molecules produced by life, and that's very exciting.'..."
The article explains that the new analysis started when folks looked at what the Phoenix Mars lander found: perchlorate, a chemical that contains chlorine. If perchlorate and the Viking life experiment's machinery got together, organic compounds in the Martian soil could have been destroyed, leaving chloromethane and dichloromethane. Which would explain the 'peculiar chemistry' that wasn't at all what researchers expected.
There's the possibility that the 'peculiar chemistry' may have been what was left after Martian microbes got deluged with water: and exploded. Someone came up with an intriguing way that critters not all that unlike Terrestrial microbes could live in a nearly-water-free place like Mars. (March 5, 2009)
The Lemming doesn't think that the 'exploding Martians' idea is very likely: but it's plausible. The researcher who came up with it deserves credit for realizing that Mars isn't Earth. And that critters (if any) living there would be adapted to a thin carbon dioxide atmosphere and almost no water. Not the thick nitrogen-oxygen mix blanketing the comparatively soggy Earth.
Organic compounds aren't life, as the article points out. But they're what life is made of - life-as-we-know-it, anyway. The possibility that Mars has organic stuff on its surface means that the next Mars rover mission should probably have its payload reconsidered. The Lemming thinks it makes sense to test for organic compounds on the planet. Preferably, tests designed with Martian conditions in mind.
Then, if those tests come back positive, more research to find out if the compounds come from critters.
Sooner or later, the Lemming thinks, someone's going to think of putting a microscope on a Mars lander. No matter what 'peculiar chemistry' Martian microbes have, odds are that at least some of them move.
- "Mars isn't Earth, Earth isn't Mars: And Why That Matters"
(May 12, 2010)
- "Life on Ceres? Could Be"
(March 5, 2009)
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