Check that meteorite for arsenic traces

Last December, when NASA scientists Ronald Oremland and Felisa Wolfe-Simon announced that a certain strain of bacteria had apparently swapped out phosphorus for arsenic in their makeup. This was weird--albeit plausible, since arsenic sits directly under phosphorus in the Periodic Table. (An analogous relationship between silicon and carbon is what makes some Sci-Fi writers, and some anticipators of the Age of Intelligent Machines (if there is a difference), think that there could be silicon-based life in the universe, at least in the future.) The announcement, coming as it did from NASA, had a good deal of credibility at first, and sparked a lot of speculation about the possibility that life elsewhere could look very different from life on Earth. But it turned out that the journalistic hype surrounding and preceding the announcement was overblown; critics swarmed in to denounce both the science and the publicity. It got very contentious, and very public.

This time people are being more careful. NASA astrobiologist Richard Hoover has published his conclusions--that the fossilized record of bacteria can be clearly read in ancient meteroites--in the respected Journal of Cosmology, and the Journal accompanied the publication with the announcement,in what does seem a teensy-bit defensive-sounding tone:

Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5000 scientists from the scientific community to review the paper and to offer their critical analysis. Our intention is to publish the commentaries, both pro and con, alongside Dr. Hoover's paper. In this way, the paper will have received a thorough vetting, and all points of view can be presented. No other paper in the history of science has undergone such a thorough analysis, and no other scientific journal in the history of science has made such a profoundly important paper available to the scientific community, for comment, before it is published. We believe the best way to advance science, is to promote debate and discussion.

(The commentaries, to be published over the next few days, can be accessed at this link.)

So let's not have anyone saying that we didn't understand the big implications, OK?

Extraordinary claims require extraordinary preemptiveness.

Well, this doubtless says something about the way science works in this "new era" of hyper-connectedness. Science remains (so far) an all-too-human enterprise. Be that as it may, it's interesting to contrast Hoover's findings with Oremland and Wolfe-Simon's. The latter were suggesting that there was reason to think life might look very different elsewhere in the universe where conditions could be otherwise. The former is saying that perhaps life got here from (possibly very) far away and yet could have looked more or less like what we have on our own planet. Leaving aside the question of the solidity of the science, however, I'm don't see why both might not be the case.