Well, they will be in a little over two hours, anyway.
The NASA site is a little slow right now, being pummeled by folks. I\’ll get a link as soon as I can. (EDIT: LINK) But in short: NASA announced a few days ago that they were going to hold a video conference about a new \”astrobiology\” finding. And just today, they\’ve leaked what it was all about: scientists have discovered a new bacteria here on Earth unlike any other life form we\’ve discovered.
Every bit of life we\’ve seen to date has used phosphorus as one of the building blocks of its DNA. This bacteria doesn\’t use phosphorus. It uses arsenic instead.
No, this is not an announcement about little green men. =)
But it could shape our view about \”what is life?\” And it will definitely alter our ideas about what the baseline requirements are for life to exist someplace. We\’ve surmised, for instance, that life could be based upon silicon instead of carbon. This is the first real world example of that sort of element-exchange that we\’ve seen.
Did this life form appear on Earth, the same way all the phosphorus versions did? Did it come from elsewhere? We\’ve seen some evidence that micro-organisms *might* (and I stress the might!) be able to survive within meteors to travel between planets. If this turns out to be evidence of panspermia theory, then again it might change the way we view just about everything. Even if it came into being right here on Earth, the existence of this life form is going to teach us a lot about life. Fun stuff, interesting times!
Oh come on – I write science fiction. How could I *not* write about this one?? =)
FWIW, the bacterium CAN use arsenic in lieu of phosphorus, but it naturally uses phosphorus as well; this was about the proof of concept for substitution, not that it ONLY has arsenic-based biological molecules.
Also, it was found in Mono Lake, in Northern California, which is three times saltier than sea water, and has very high concentrations of arsenic. A microbial sample from the site, when placed in phosphorus-free environment, bred microbes that took up arsenic in many sites normally occupied by phosphorus, notably as the uprights in the double-helical structure of DNA/RNA, and in ATP, reformulated here as ATAs.
No evidence of panspermia, but our criteria for what we look for when we look for life elsewhere in the cosmos just got broader. 🙂
FWIW, the bacterium CAN use arsenic in lieu of phosphorus, but it naturally uses phosphorus as well; this was about the proof of concept for substitution, not that it ONLY has arsenic-based biological molecules.
Also, it was found in Mono Lake, in Northern California, which is three times saltier than sea water, and has very high concentrations of arsenic. A microbial sample from the site, when placed in phosphorus-free environment, bred microbes that took up arsenic in many sites normally occupied by phosphorus, notably as the uprights in the double-helical structure of DNA/RNA, and in ATP, reformulated here as ATAs.
No evidence of panspermia, but our criteria for what we look for when we look for life elsewhere in the cosmos just got broader. 🙂