NASA's curiously worded press release earlier this week about an event later today prompted speculation that the space agency had discovered extraterrestrial life; going by a leak ahead of conference, it's actually something about as alien as you can get from physiology as we know it, only on this very planet. According to NOS, NASA has found a new type of bacteria in Mono Lake, California, which lives with levels of arsenic in its biology that were hitherto believed impossible.
That alone is enough to make it significantly different from all life we've encountered to date - human, animal, plant or microbial - which regularly consists of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur but to which arsenic is deadly. It's unclear whether NASA will announce that this new bacteria swaps out the phosphorus in its DNA for arsenic, or merely utilizes the poison in some way.
The announcement is the culmination of many months work by geobiologist Felisa Wolfe-Simon, who theorized earlier this year that the unusual ecosystem at Mono Lake could have led some life to follow a different "evolutionary pathway." While the announcement doesn't include little green men on another world, it does significantly broaden the possibility of what life may be possible on other planets with different environments:
"It may prove that there are other possibilities that are beyond our imagination. It opens the door for us to think about biology in ways we have never thought. We are going to look for life on other planets and we only know to look for that which we know. This may help us to develop tools to look for something we have never seen." Felisa Wolfe-Simon