WASHINGTON — NASA’s announcement that it would hold a press conference Thursday to discuss a finding that would “impact the search for evidence of extraterrestrial life,” whipped alien true believers into an Internet frenzy, rife with speculation that new life forms truly were “out there.”
As it turns out, they were here all along.
Scientists led by NASA astrobiologist Felisa Wolfe-Simon, have discovered a new life form in a California salt lake whose chemical makeup is unlike any organism known to man, according to a study that will be published in the journal Science Friday. Instead of phosphorus, a chemical building block shared by all other known life on earth, this novel bacteria thrives on arsenic, a compound poisonous to most creatures.
Wolfe-Simon’s energetic and theatrical presentation of her findings imbued the conference with a tone of unique historical significance.
“We’ve cracked open the door to what’s possible for life elsewhere in the universe,” she said. “And that’s profound – to understand how life is formed and where life is going. This microbe substitutes arsenic for phosphorus in its basic biomolecules. What else might we find? What else might we want to look for?”
While disappointing to some viewers of the live-streamed conference who expected the unveiling of a real-life E.T., the finding has huge implications in the search for extraterrestrial life.
“This is a phenomenal finding,” said NASA’s director of astrobiology Mary Voytek. She went on to compare the discovery of the arsenic-using microbe, called GFAJ-1, to “the Horta,” a fictional one-of-a-kind silicon-based beast from the original “Star Trek” series.
“This is, in our mind, the equivalent of finding that Horta,” Voytek said with pride.
Scientists currently search for six essential chemical elements when hunting for signs of life on distant planets: carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur.
This discovery will force astrobiologists to broaden their perspective.
“I find this result delightful because it makes me have to expand my notion of what environmental constituents might enable habitability,” said NASA astrobiologist and mineralogist Pamela Conrad, who joined Wolfe-Simon on stage during Thursday’s conference. “It opens up a whole new line of questioning.
The finding also could serve numerous practical purposes as it relates to phosphorus, explained James Elser, an ecology professor at Arizona State University who has studied the element for his entire career.
“As someone who…regularly gives lectures about phosphorus in which I state that every living thing uses phosphorus to build its DNA,” Elser said, chuckling. “The idea that I’m sitting here today discussing the possibility that that’s not true is quite shocking. So Felisa, I have to thank you and blame you for making our lives somewhat more difficult.”
Phosphorus, which is commercially used as an organic fertilizer because it is essential for plant growth and proliferation, is often a limiting factor due to its lack of natural abundance.
“There’s some concern among scientists that supplies of phosphorus that support the green revolution and high agricultural production might become scarce,” Elser said. “So we need to get a lot cleverer about phosphorus in society and it’s really exciting to think about the possibilities that are raised by a clever organism that has evolved a way to do without phosphorus, possibly.”
He said that the microbe could potentially be used in waste water treatment and bio-energy production.
In her closing statement, Wolfe-Simon invoked the importance, in scientific inquiry, of keeping an open-mind and an active imagination.
“My niece asks me, ‘How did we get here?’ and ‘Are we alone in the universe?’ and it’s profound that we don’t know the answers exactly to that yet,” she said. “Maybe, not in my lifetime, but maybe in her lifetime she’ll be able to answer that. I hope my work serves as a proof of concept that we can experimentally test and show evidence of what else is possible.”
Wolfe-Simon revealed that she’s already close to finishing a second paper on the arsenic-friendly microbe, but wouldn’t reveal the findings. She said she plans to submit the paper in February.