Slashdot Mirror
Evidence of Bacterial Life on Europa
AaronW writes: "According to this article at newscientist.com, the rosy color of Europa may be caused by bacteria. Apparently the previously unexplained infra-red signature matches that of extremophile bacteria found here on Earth."
But which argument does the Razor favor?
Is it simpler to believe that a mix of salts causes both the IR spectrum and the visible coloration, or is it simpler to believe that some bacteria cause it?
We've never seen life off the Earth, but we've also never seen a lack of life in livable conditions on Earth.
We've never seen bacteria having an effect on another celestial body's spectrum, but we've never seen the combination of salts (even on Earth) that could cause this spectrum either.
I would grant that it doesn't meet Sagan's more stringent requirement that "extraordinary claims require extraordinary proof."
I also agree there's only one way to be sure...
"You can't get something for nothing." - my grandfather, on the stock market and Reaganomics.
Oddly, I was just having an argument with the head of CU's astrobiology institude about this point. Fits to surface spectra are seldom unique. It's a pain in the butt, be we can't even identify the minerals on Mars uniquely some of the time. Europa is worse. Not only do we not know the chemistry as well (rocks is rocks, and we have plenty of those on Earth), but the conditions are hard to reproduce. Temperatures of around 100 K, almost no surface pressure and a harsh radiation environment.
If you do a little digging (check back issues of Science magazine), you'll notice that there are already two theories about the mysterious absorber on Europa. There's McCord's salts theory and there's the sulfuric acid theory (put forward by Carlson). We can't distinguish between them right now. Adding another potential absorber to the fray doesn't really fundementally alter that we just can't tell right now what's down there.