Scientists working under a grant from NASA's Astrobiology Institute report they have found bacteria -- in Mono Lake, Calif., not in space -- that could be made to live on arsenic. The organism is called GFAJ-1. The finding is important because it expands the prevailing view of what it takes for living things to survive.
"Not only did this microbe cope," said Felisa Wolfe-Simon, a NASA astrobiology research fellow at the U.S. Geological Survey, "but it grew and thrived. And that was amazing."
Wolfe-Simon led a team that reported its findings online today in the journal Science, which -- hey, wait a minute. If they didn't find alien life, why was the blogosphere so wildly abuzz about it?
It all started earlier in the week with a NASA news release that, constrained by the Thursday embargo Science routinely imposes on its weekly editions, included this tantalizing line:
"NASA will hold a news conference at 2 p.m. EST on Thursday, Dec. 2, to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life. Astrobiology is the study of the origin, evolution, distribution and future of life in the universe."
Imaginations ran wild. A New York blogger named Jason Kottke looked up the participants in the news conference and found that several had published research in the past on Mars, arsenic, and Saturn's moon Titan.
"So, if I had to guess at what NASA is going to reveal on Thursday," he wrote, "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."
He soon had to take it back, warned off by a writer who knew what the paper actually said. Hundreds of reporters (this one included) are given advance access to papers in Science on the condition that they honor the journal's embargo.
All of which created an awkward situation, especially when the story took on a life of its own.
Alien Life? No, Life From Arsenic
Yahoo News contributor Brad Sylvester speculated that in the unlikely event extraterrestrial life had been found, "the best prospect for this might be from Mars."
Fox News joked, "Of course, there is always the chance that NASA has discovered alien life -- right?"
Randolph Schmid of the Associated Press, who had embargoed access to Science, wrote, "The paper will be a disappointment to those speculating about its contents. It does not report finding life outside of Earth."
He went on to explain Science's embargo system: "Because modern science can be complex and hard to explain, major journals such as Nature, Science, Journal of the American Medical Association and others make their papers available to selected science writers in advance.
"That gives the writers time to prepare their stories. In return, they are required to promise that they will abide by release times for the papers they see in advance."
Expanding the Definition of Life
So what about the actual finding? To scientists, it's actually a pretty big deal if it's accurate.
Most of life -- down to its protein, fat and DNA -- is made from just six chemical elements: carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus. In the California experiment, the researchers said arsenic compounds effectively took the place of the phosphorus in the bacteria.
"The idea of alternative biochemistries for life is common in science fiction," said Carl Pilcher, director of NASA's Astrobiology Institute in Moffett Field, Calif. "Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake."
If that can happen, what else is possible? Could there be places in the universe where silicon does what carbon does on Earth? Where other combinations happen that haven't occurred to earthly researchers, looking for life that resembles ours?
"We still don't know everything there is to know about what makes a habitable environment on another planet," said NASA's Pamela Conrad, who is on the team that built Mars Science Laboratory, the next probe scheduled to land on the red planet in 2012. "We have to increasingly broaden our perspective."
Some scientists were skeptical. Steven Benner of the Foundation for Applied Molecular Evolution called the finding "an exceptional result" -- but said that was precisely the problem with it: GFAJ-1 may just be a fluke. Compounds containing arsenic would probably fall apart more easily than those with phosphorus.
Other scientists later criticized the paper, saying the team had not proved the bacterium was actually using arsenic compounds in place of phosphorus. See more HERE.
Still, today's report could be big, said Keith Cowing, who runs the website NASA Watch. "It shows that other biochemistries are possible, more than just 'life as we know it' and that the possible places where 'life' could exist in the universe are now much more numerous as a result."
"We've cracked open the door to what's possible for life elsewhere in the universe," said Wolfe-Simon, the lead researcher. "And that's profound."