To quote the song “Star Trekkin’,” “It’s life, Jim, but not as we know it.”
NASA has found a new form of life. But it wasn’t in the distant reaches of outer space. It was here on our home planet of Earth.
NASA revealed yesterday the discovery of a bacteria in a mud sample from California’s salty Mono Lake that is the first-known organism to use arsenic in its basic metabolism and genes.
The finding would add deadly arsenic to the six basic elements believed needed for life — carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus. The six elements are such a fundamental tenet of biochemistry that finding a critter living on arsenic was a big surprise.
“It’s doing something extraordinary,” says team leader Felisa Wolfe-Simon of the NASA Astrobiology Institute in Menlo Park, Calif.
“This is an exceptional claim,” said biochemist Steven Benner of the Foundation for Applied Molecular Evolution, in Gainesville, Fla. Though skeptical, Benner says if confirmed, the finding would suggest that life could function on other worlds, such as Saturn’s frigid moon, Titan, where arsenic-based biochemistry could thrive.
“This is a transformational result for the field,” says astronomer Dimitar Sasselov of the Harvard Origins of Life Initiative. “It goes back to the basic question of what is life, really?”
FINDING: Arsenic-munching microbe excites astrobiologists
Astronomers have detected more than 500 planets orbiting nearby stars in the past two decades, raising expectations that future telescopes may peer at them for chemical signatures of life. If life can thrive on unexpected elements such as arsenic, Sasselov argues, the possibilities for alien life could widely expand.
Life on Earth depends on phosphorus as a key element in nutrients. The new bacteria, however, appears to partly swap out arsenic for phosphorus.
In the study, the team grew generations of the bacteria in an arsenic-laced experiment, usually deadly to such microbes, and were surprised to see the bacteria thrive instead. “Life is extremely adaptable,” says biochemist Jim Cleaves of the Carnegie Institute of Washington (D.C.). Yet, he’s more skeptical that the arsenic finding could mean much about alien life. “We already knew bacteria in lakes live pretty close to the edge.”
NASA’s announcement of a news conference that would “impact the search for evidence of extraterrestrial life,” sparked a great deal of speculation. Mary Voytek, head of NASA’s Astrobiology Program, said “I’m sorry if they are disappointed” for anyone expecting NASA to produce evidence of alien life.
Lejon from Chandler says
Why do I have the words “Andromeda” and “Strain” going through my head right now?
Sam says
I think it simply proves that life, is unstoppable in finding ways to find expression and survivability.
Bill from Albuquerque says
All this does is to remind scientists of all disciplines is that your search or other types of parameters should be open to adjustment if the evidence is there that they might be set too stringent. This also proves that the high temp areas of underwater volcanic vents aren’t the only place on Earth that differing forms of life can exist. Now if this can be confirmed along with the methane breathing microbes that was reported on earlier this year being found in the ice in Canada, then we should start booking probes to Titan and maybe Europa plus sending a few to probe the atmosphere of Venus that might surprise us with the results of scans. Besides, who is to say that there is not a silicon based life form on one of the exoplanets we know of at the moment that can move through rock like we move through air that our current technology has prevented us from finding evidence of?