In a much-anticipated — and for many, disappointing — announcement, NASA said it found microbes that can use arsenic as one of the building blocks of its DNA.
BY FRED TASKER
The NASA announcement created an enormous Internet buzz: The space agency was going to reveal Thursday “an astrobiology finding that will impact the search for evidence of extraterrestrial life.”
Was the government about to say it had found liquid water on a moon of Jupiter? Microbes on Mars? Something even stranger — say, ET?
Sci-fi bloggers speculated the announcement “could prove the existence of aliens” or “the theory of shadow creatures that exist in tandem with our own.”
But then the announcement came and it was about . . . bacteria right here on Earth.
At a 2 p.m. news conference streamed live over the Web, scientists at the National Aeronautics and Space Administration said they found microbes in the mud beneath a California lake that can use arsenic — usually considered toxic — rather than phosphorus as one of the building blocks of its DNA. Phosphorus is one of the elements that sustains all other life forms on earth.
After their great anticipation, sci-fi fans were told the discovery might help cut pollution of waterways like Lake Okeechobee by replacing the phosphorus in fertilizers that run off into the lake, creating fish-choking algae blooms.
One of the NASA researchers acknowledged the frustration after the build-up: “I can see you’re disappointed, that some of you were expecting walking, talking aliens,” said Felisa Wolfe-Simon, a NASA astrobiology researcher and co-author of the study.
“It would be incredible to announce that we have found an alien. But from our understanding of biology, this is a phenomenal finding. You’re taking the fundamental building blocks of life and replacing one of them with another compound.”
She even tried to put a sci-fi spin on it: “This is the equivalent of the Star Trek episode in which they found life forms on a distant planet that substituted silica for carbon in their basic makeup.
“Maybe we can find ET now because we have a better idea of what we’re looking for.”
After the news conference, a University of Miami scientist good-naturedly speculated on what Thursday’s announcement might mean for the shape of life on other planets.
“This is a pretty big deal,” said Athula Wikramanayake, a UM expert in evolutionary biology. “We’ve always believed that the basic elements needed for life are carbon, nitrogen, hydrogen, oxygen, sulfur and phosphorus,” he said.
On a planet whose atmosphere is rich in arsenic, “we wouldn’t expect anything resembling humanoids. It’s very unlikely they would look like humans.
Wikramanayake agreed with famed physicist Stephen Hawking, who in a newspaper interview in May pointed out that any aliens who arrive on earth from billions of miles away logically will be far more advanced than planet-bound earthlings.
“If aliens ever visit us,” Hawking warned, “I think the outcome would be much as when Columbus first landed in America — which didn’t turn out very well for the Native Americans.”
“It’s possible,” said Wikramanayake.
“Some planets are billions of years older than earth. They’ve had a lot of time to evolve.”
Does he agree such aliens would be hostile?
He left a ray of hope: “It’s hard to say whether they would be as aggressive as humans. Humans evolved because of tribal fighting. Aliens might not have the same social history.”