November 20, 2012

Extremophiles, Archaeans, Biogenic Stromatolites, and Mars

When a scientist teases the whole world about an "earthshaking" discovery on Mars, you just can't help but think what it might be. In the age of social media, you can't help but tweet about it. I was going to tweet about extremophiles on impulse but I decided to dig (no pun intended) a little bit further to be more specific and to put more substance into my tweet. For some reason, the word "Stromatolites" came up in my mind. But "Archaean Stromatolites" is a better deal. But now I think "Biogenic Stromatolites" is way much better.

Some Archaeans are extremophiles and this gives me a good reason to post about it here (because I love extremophiles!) In turn stromatolites are sedimentary structures produced by the activities of microorganisms (such as archaeans) in shallow water. They precipitate calcium carbonate or limestone when they metabolize. Putting together the clues that I know, such as the evidence that water once flowed on Mars, I would think that if they ever existed, these early martian single-celled critters (which I would temporarily equate with archaeans for lack of a better term) must have formed mats of stromatolites or calcites and their signature became fossilized, and then eons later this badass curiosity rover came along and scooped up some of it and unpacked the chemical evidence with its SAM instruments and beamed the data to earth. And then one Geologist got so excited that he remarked “This data is gonna be one for the history books," and then everyone got crazy on twitter.

Well, a little sleuthing about what would make a geologist so excited points me to this paper (PDF) which I think pretty much sums up most of the clues regarding the puzzle. I'm guessing the findings would be similar, i think, but the main idea is that evidence of fossilized by-products of ancient forms of life on the red planet may have been found by Curiosity. Or could just be organic chemicals, upon which further study is needed to know if it is biogenic or abiotic. But definitely the discovery is not Life itself but perhaps (or maybe i am just hoping) it may be microfossils or some ancient signature of simple lifeforms in the distant past. And so, with that little background you know what I'll tweet about. Of course I may be wrong most probably, but tweeting with some substance is better than tweeting some senseless snarkiness. And relax, it's just a tweet about a wild guess.

No comments: