NASA announced Thursday it has discovered alien life - in California, natch.
In a bombshell that upends long-held assumptions about the basic building blocks of life, scientists have discovered a a whole new type of creature: a microbe that lives on arsenic.
It is unlike every other lifeform on the planet - from the simplest plant to the most complex mammal.
"It's terrestrial life - but not life as we know it," said Mary Voytek, director of NASA's astrobiology program.
All life so far discovered by scientists is composed of combinations of the same six elements: carbon, hydrogen, nitrogen, oxygen, sulfur and phosphorus.
But Felisa Wolfe-Simon, a scientist at Arizona State University's School of Earth and Space Exploration, found a strain of Halomonadaceae bacteria on the bottom of California's volcanic Mono Lake that lives without any phosphorus.
Instead, it uses arsenic to build cells. On its DNA strand, where phosphorus should be, is instead arsenic.
The implications are profound. Astrobiologists looking for life on other planets may be able to vastly expand their search to places with non-Earth environments.
"We've cracked open the door to what's possible for life elsewhere in the universe," said Wolfe-Simon. "What else might we find?"
NASA planetary scientist Pamela Conrad said "the implication is that we still don't know everything there is to know about what might make a planet habitable."
ASU professor James Elser called the finding "shocking," noting ruefully that he has been telling his classes for decades that all life needs phosphorus.
"It really is quite a remarkable report," he said.
Read more: NASA announces discovery of alien microbe that lives on arsenic in California's volcanic Mono Lake