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NASA Announcement Broadens Understanding Of Life In The Universe

California's Mono Lake hosts bacteria that scientists say may redefine life as we know it.
Rumors swirled for days. The blogosphere was abuzz. Newspapers ran photos of E.T. and slime-covered, fang-toothed creatures from the “Aliens” movies.

Anticipation reached a near fever-pitch leading up to the December 2 announcement by the U.S. National Aeronautics and Space Administration (NASA) of what it described cryptically in a press release as a “finding that will impact the search for evidence of extraterrestrial life.”

And while the answer to the ultimate question – ‘Are we alone in the universe?’ – remains elusive for now, a team of scientists has announced a discovery that shows life is more interesting than we had thought, right here on Earth.

"The bacterium... has solved the challenge of being alive in a very different way," said Felisa Wolfe-Simon, a NASA astrobiology research fellow who led the team that has revealed a startling new form of life -- one that has adapted its cellular architecture to a toxic environment.

Life As We (Now) Know It

The organism is a strain of the Halomonadaceae bacteria known as GFAJ-1 and is found in California’s Mono Lake.

No ordinary body of water, this one is loaded with arsenic, an element once thought to be poisonous to all organisms.

But NASA’s Wolfe-Simon found that not only does the microbe derive its fuel for life from arsenic, it actually integrates the poison into the fabric of its DNA and other basic parts of its cells.

In fact, it substitutes arsenic for phosphorus, which is one of the key components of cellular structures of all previously known life forms.

Lewis Dartnell, an astrobiologist at University College London’s Center for Planetary Sciences, said the discovery changes human understanding of the parameters of life.

"All we've known about life so far is that it uses elements such as carbon, hydrogen, oxygen, nitrogen, sulfur, [and] phosphorus -- that all life is basically combinations of those elements stuck together into big, complex molecules. So this discovery of a bacterium that can start substituting arsenic for phosphorus is a very exciting discovery," he said. "It's starting to change the basic biochemistry -- the building blocks of life as we understand it."
Wolfe-Simon: The bacteria "has solved the challenge of being alive in a very different way."

Science has known for decades about ‘extremophiles’ -- life forms that survive in the harshest conditions, adapting to boiling hot acid, the sunless bottom of the ocean, or frigid water inside icebergs.

This arsenic-loving microbe was itself discovered two years ago, but its unique ability to swap arsenic into its DNA was only just revealed.

New Chance For Extraterrestrial Life?

Experts are saying the discovery of a new type of cellular architecture quite literally opens up new worlds of possibility.

Sara Seager, a professor at the Massachusetts Institute of Technology who studies habitability for life on other planets, said that up until now, most of the research in the field has looked for other forms of life in places that have Earth-like conditions, where the only known life exists.

That assumption led scientists to study planets like Mars and the moons of Saturn and Jupiter.

Now, Seager said, that search can be expanded.

"This opens up a huge possibility for people to imagine what other kinds of life forms could be out there. In particular, we like to think about the possibility of life on Mars, life on [Saturn’s moon] Titan, and life elsewhere on other planets beyond our solar system, [but] this really gives us the permission to think more broadly," she said.

NASA’s discovery caused amazement in the scientific community.

On Twitter, the public chimed in from Germany, Japan, Portugal, and elsewhere.

One user quipped, “I’m going to pour myself a nice chilled glass of arsenic on the rocks to celebrate.”

Philip Plait, the author of the “Bad Astronomy” blog for the U.S. popular science magazine “Discover,” tracked the public fervor in the days leading up to the announcement.

He said that while many people are likely to be excited, some may feel let down that the announcement wasn’t about little green men on another planet.

"If a bacterium can substitute one element for another one when one of them is toxic and the other one is necessary for life, that's really cool. But compared to finding E.T., I think a lot of people might be disappointed by that," he said.

Indeed, following the announcement, one Twitter user wrote, “I think we were all waiting for something more than bacteria.”

NASA’s Wolfe-Simon, however, said the disappointed masses are underestimating the discovery.

"What other questions can we ask?" Wolfe-Simon asked. "This will inform us about life on our own planet and it will help inform us of life -- we will find it one day -- elsewhere in the universe."

The scientific paper describing the breakthrough was to be published December 3 in the journal “Science.”

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