Are Aliens Among Us? Sort of, NASA Says

A scanning-electron micrograph image of arsenic-eating bacteria, which NASA says has redefined the quest for life in the universe. (Science/AAAS)

Alien life has been among us all along, according to new biological findings announced by NASA Thursday.

Research conducted by biochemist Dr. Felisa Wolfe-Simon from the U.S. Geological Survey has turned the quest for alien life on its ear, suggesting that phosphorous, carbon, and the other fundamental elements found in every living thing on Earth aren’t the only signs of life. Wolfe-Simon explained the findings at a hotly anticipated NASA press conference on Thursday.

After a two-year study at California’s Mono Lake, near Yosemite National Park, Wolfe-Simon found that a bug will grow in the presence of the toxic chemical arsenic when only slight traces of phosphorous are present. It’s a radical finding, says molecular biologist Steven Benner, who is part of NASA’s «Team Titan» and an expert on astrobiology — forcing the space agency to redefine the quest for other life in the universe.

«When we’re searching for alien life, if it’s not a Ferengi from Star Trek, what would it be?» Benner asked In his estimation, we’ve always defined life as something that has the exact same chemistry as a life-form on Earth. The new discovery will likely change that equation, because it means the basic building blocks of DNA are not quite what we thought.

Benner, said the arsenic-loving organism at Mono Lake grew without high levels of the nutrient phosphate (although some phosphates were still present). Just as important, it could change how we look for alien life on other planets, especially on Saturn and the moons of Jupiter.

«It’s a paradigm shift,» says Dimitar Sasselov, an astrobiologist who leads the Origins of Life Initiative at Harvard University. «The possibility that Earth-life biochemistry is not universal is a transformational concept. It fills the search [for alien life] with optimism. NASA is moving in a good overall direction. What is needed is to take alternatives for life’s chemistry to heart and fund research work better.»

Arsenic is poisonous to nearly all forms of life on earth. Even small amounts of the poison become embedded in living tissue, causing liver failure and ultimately death — in nearly everything BUT these bacteria.

However, as science fiction author Robert Sawyer told, there could be even more profound implications. We have always looked for alien life that matches our biology, but now we have found a different life-form that uses arsenic in its basic DNA structure, he said.

Sawyer explained that NASA science probes have always looked in the most likely places we thought life could exist — on Mars or Europa, a moon of Jupiter. There is an old joke, he says, about how someone lost a quarter in their garage, then looks out in the yard for it. A neighbor asks why they are looking there instead of in the garage; the light is better, he answers.

«We tend to use the tools we know and the places we know to look for alien life,» Sawyer said, explaining that humans want to find a walking, crawling alien and not one that just has different DNA.

The change, he says, is that NASA will start looking for arsenic as well, and possibly other chemicals. This could mean new missions to Titan, which is known for having traces of arsenic. Another change could be the scientific equipment we send to space – probes might be retrofitted to search for arsenic.

Benner said the finding even impacts earlier research. Several years ago, when a Martian meteorite crash-landed on Earth, scientists examined it for the presence of phosphates. Now, it may be possible to re-visit some of the earlier findings. This hints at what experts call the «shadow biosphere» — the existence of other life-forms, even on Earth, that have a radically different DNA structure.

«It’s a huge breakthrough. It changes the probabilities for their being life on other planets,» Sawyer told «If there is more than one recipe that makes life, then there are chances of rolling the dice in a chemical soup of all over the universe, and the chances of that chemical soup giving rise to life is much larger.»

For NASA, the scientific discovery could help the agency acquire new funding, serving as a catalyst to convince Congress to green light for new missions to Mars or Titan.

In fact, the Internet buzz about finding alien life, as Sawyer noted, is partly due to how NASA has timed the announcement. A new Congress means new opportunities for scientific missions. He says the reality of the finding is somewhat of a joykill — we have not found E.T. — but there are still major implications for science and the search for extra-terrestrial life in our solar system and beyond.

Benner says the findings need further review — there are questions about how much phosphorous is needed to sustain life.

«The next phase is to grow more of the stuff in a lab using a defined cultured, maybe cook up a broth that contains no phosphorous at all, look at this with a critical eye,» he said.

However you view the announcement, the Lake Mono findings are profound, and the possibilities for finding life — especially the primordial kind — are now even greater.

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