Arsenic & New Life
E.T. close to home? Discovery of new life opens up a new search for aliens
It's pretty well-known that NASA scientists spend their days looking for new forms of life in the universe. But it wasn't expected they'd find one on Earth.
NASA astrobiologists have discovered a microorganism in California's toxic Lake Mono that grows and reproduces using arsenic, a chemical that's typically poisonous.
"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's headquarters in Washington during a press conference. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it."
Before Thursday, all known forms of life were made of six essential building blocks: Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. The newly discovered microbe, known as strain GFAJ-1, substitutes arsenic for phosphorus, which has been considered essential in organisms for its role in DNA and RNA as well as its function in cell membranes.
"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new — building parts of itself out of arsenic," said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the eight-person research team's lead scientist. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"
The discovery of an alternative biochemistry makeup will rewrite the definition of life in textbooks and change the search for extraterrestrial life, according to NASA. In proving that life can be created from unknown or atypical elements, the discovery opens the door for a wider possibility of life beyond Earth.
Says Wolfe-Simon, "All life we know is the same biochemically, and this is a little different. It is suggesting there is another way to be alive."