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Plenty of speculation and hype about a media advisory issued by NASA earlier this week, which says that a press conference will be held on Thursday (Dec 2) “to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life.” Naturally, this sentence has got a lot of people excited about the possibility that NASA has discovered ET life…though the wording (“impact the search”) reads more to me that they have uncovered something which changes the ball-game somewhat.

One blogger has dug into the backgrounds of the scientists who will be present at the press conference to try and get a better idea of what this enigmatic “astrobiology finding” is:

I did a little research on the news conference participants and found:

1. Pamela Conrad (a geobiologist) was the primary author of a 2009 paper on geology and life on Mars

2. Felisa Wolfe-Simon (an oceanographer) has written extensively on photosynthesis using arsenic recently (she worked on the team mentioned in this article)

3. Steven Benner (a biologist) is on the “Titan Team” at the Jet Propulsion Laboratory; they’re looking at Titan (Saturn’s largest moon) as an early-Earth-like chemical environment. This is likely related to the Cassini mission.

4. James Elser (an ecologist) is involved with a NASA-funded astrobiology program called Follow the Elements, which emphasizes looking at the chemistry of environments where life evolves (and not just looking at water or carbon or oxygen).

So, if I had to guess at what NASA is going to reveal on Thursday, I’d say that they’ve discovered arsenic on Titan and maybe even detected chemical evidence of bacteria utilizing it for photosynthesis (by following the elements). Or something like that.

However, a journalist who has seen the scientific paper was quick to dismiss speculation about the discovery of ET life (though due to embargo could not say what it was actually about).

Probably the most sane line of thinking is that the announcement will be about arsenic-based life-forms – either the discovery of actual examples here on Earth, or at least a less sensational (though equally interesting) proof of their viability. Both of these are mentioned by Dr Wolfe-Simon on her website as current projects – one of which includes another of the scientists on the panel (Dr Benner) – designed to scientifically test “the likelihood of life arising to either originally incorporate arsenate in a functional sense, and/or more speculatively, alternative forms of life utilizing a genetic system entirely based on arsenic”:

To futher this hypothesis, we have embarked on two different approaches to test assimilatory arsenic utilization. Firstly, as part of the NASA Astrobiology Institute we are examining arsenate-rich environments to hunt and enrich cultures for organisms utilizing arsenate in novel and unique modes…

In concert with this in situ and/or in vivo type work, we are also collaborating with Dr. Steve Benner and Dr. Nicole Leal at The Foundation for Applied Molecular Evolution and Dr. Marcelo Guzman to measure the spontanous incorporation of arsenate into a DNA backbone.

Given the work with Dr Benner, smart money would have to be on “spontaneous incorporation of arsenate into a DNA backbone” methinks. Though the discovery of a ‘shadow biosphere’ at somewhere like Mono Lake would be a bit more exciting…