IOS 7

NASA Discovers Arsenic-Fed Life Form

NASA has discovered a new life form that can grow by substituting arsenic for phosphorus, redefining the agency's search for different life forms other than the ones known on earth.

The discovery was made by astrobiologists who performed tests by taking mud from Mono Lake -- a body of water in Northern California three times as salty as the ocean -- which has high arsenic content, said Felisa Wolfe-Simon, a NASA astrobiology research fellow with the U.S. Geological Survey, during a press conference Thursday.

Researchers created an environment that had everything else a typical life form that exists on earth would need to survive, except for phosphorus - which is one of the building blocks of all existing life forms. Instead, they used arsenic -- normally a toxic element to existing life forms -- to replace phosphorus, she said.

To their surprise, a microbe not only was able to tolerate the toxicity, "but it grew and thrived," Wolfe-Simon said. "Nothing should have grown."

The experiment has widespread ramifications for how NASA will search for other signs of life, she said.