Mars isn't Earth, Earth isn't Mars: And Why That Matters

"Earth Microbes Not Likely to Contaminate Mars, Scientists Say"
Space.com (May 10, 2010)

"Scientists have long been concerned with the possibility that their search for any signs of life on Mars could be thrown off-course by wayward microorganisms from Earth that hitch a ride to the red planet on man-made spacecraft. But a new study suggests that fear may be less likely than researchers once thought.

"While some bacteria could potentially survive the harsh trip through space, Mars atmospheric entry and landing, they would most likely die soon after landing on Mars because of the planet's harsh atmosphere, the study found.

"Ultimately it is unlikely such microorganisms will be able to replicate once on the Martian surface, the research suggests...."

Unlikely, certainly. But I remember when it was assumed that there couldn't be anything living in hot springs. Now biologists study extremeophiles.

Maybe the conclusions of this study will seem like 'famous last words' a few decades from now.

On the other hand, I'm pretty sure that anything from Earth wouldn't find Mars hospitable. Things are different there. The near-total absence of liquid water available, for starters.

It could work both ways. There's an interesting bit of informed speculation that the 'peculiar chemistry' in the failed(?) Viking life experiment was what you get when Martian microbes are exposed to ridiculously overwhelming (for them) amounts of water. (March 5, 2009)

The article describes what's being done to keep organic contamination on spacecraft to a minimum, and shows Mars rover Curiosity being assembled in one of the Jet Propulsion Laboratory's 'clean rooms.'

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Other posts, about

• "Mars, Mostly"

Related posts, at

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"