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Mars Robot May Destroy Life It Was Sent To Find
Hugh Pickens writes "New Scientist reports that instead of identifying chemicals that could point to life, NASA's robot explorers may have been toasting them by mistake. Even if Mars never had life, comets and asteroids that have struck the planet should have scattered at least some organic molecules over its surface but landers have failed to detect even minute quantities of organic compounds. Now scientists say they may have stumbled on something in the Martian soil that may have, in effect, been hiding the organics: a class of chemicals called perchlorates. At low temperatures, perchlorates are relatively harmless but when heated to hundreds of degrees Celsius perchlorates release a lot of oxygen, which tends to cause any nearby combustible material to burn. The Phoenix and Viking landers looked for organic molecules by heating soil samples to similarly high temperatures to evaporate them and analyse them in gas form. When Douglas Ming of NASA's Johnson Space Center in Houston, Texas, and colleagues tried heating organics and perchlorates like this on Earth, the resulting combustion left no trace of organics behind. "We haven't looked the right way," says Chris McKay of NASA's Ames Research Center. Jeffrey Bada of the University of California, San Diego, agrees that a new approach is needed. He is leading work on a new instrument called Urey which will be able to detect organic material at concentrations as low as a few parts per trillion. The good news is that, although Urey heats its samples, it does so in water, so the organics cannot burn up."
For the benefit of new readers and the general perspective; an old short-story by Terry Bisson: http://www.netfunny.com/rhf/jokes/96q1/meat.html
It's a "must read" if you haven't, just give in and click the link.
The title is very misleading.
No-one thought that heating samples to 400 or 600 C would be good for any bacteria. The point is that they thought samples would outgas any organics. Now it seems they might be burned in the process. But in neither case were these tests designed to keep microbes alive.
Note that one implication here is that Martian soil will burn even under Martian conditions if you heat it properly - it has its own oxygen supply.
Martian bonfires anyone ?
Ah, the Human way of finding life:
Astronaut 1: "So, any signs of life?"
Astronaut 2: *shooting a flamethrower at the ground* "None."
Astronaut 1: "Ok, just to be sure let's blow everything up and scan the debris."
In Cosmos, Carl Sagan mentions an experiment that got scrubbed off of the Viking probes because of a lack of room. I forget the scientist who cooked up the idea (Wolf-something??), but it was really simple. Send up a container of food for whatever life you're expecting, throw some dirt in their, and see if anything develops. It was basically a petri dish for Mars.
"Wouldn't you want to use an IR Spectrometer?"
A number of infrared spectrometers have been sent to Mars, both on orbiters and rovers. It is, however, very difficult to see the spectroscopic signature of organics when they are at low concentrations in a soil/mineral matrix.