Motherboard

“I’m sorry if they are disappointed.”

That’s how Mary Voytek, director, Astrobiology Program, NASA Headquarters, actually responded to a USA Today reporter at a press conference today, in response to a question about how doggone annoyed newspaper readers and internet users were that NASA didn’t discover a giant space alien, but only a measly microbe that can live on arsenic alone, a finding that blows apart our definition of Life and could help us find aliens in the future.

She had to remind everyone, half sheepishly, half Kindergarten-teacher, near the end of an hour-long press conference, that “that there are lots of people … that see this as a huge finding.” The exchange is here, at 4.55:

Where Are Our Aliens

The announcement, and the wild speculation it generated ahead of time, underscored just how excited the public is about science – provided that science involves Eureka-type discoveries of space aliens, likely using robots or machines that could swallow the Earth in a black hole. Blame may lie with the blog editors and owners reporting on that kind of science. They may argue that they’re only following public taste, but they’re also probably not talking about science. Science would be, as an excited Felisa Wolfe-Simon, the NASA astrobiology research fellow who led the research, said meant “thinking about life… and asking questions, simple questions, with simple experimental design.”

NASA also isn’t faultless. The agency’s valiant but unsatisfying efforts at educating the public about what they do seem to have gotten lost somewhere between debates about the need for the space agency, confusion over its mission, and a public that’s more interested in new Earths and aliens than in elusive molecules or weather patterns.

It’s that audience that NASA may have had in mind when it wrote that tantalizing email on Monday. It began,

NASA will hold a news conference at 2 p.m. EST on Thursday, Dec. 2, to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life. Astrobiology is the study of the origin, evolution, distribution and future of life in the universe.

See, there’s your problem right there, NASA: use the words “evidence of extraterrestrial life” in the first paragraph of your email (“you” being the world’s leading space agency, which never officially talks like Agent Mulder), and you are going to send a million thumbs a Tweeting and RTing all around the black hole of the Internet.

See Ten Quick Reasons We Really Want There To Be Aliens

This problem – aiming to excite an over-stimulated public by sensationalizing science – isn’t new for NASA either. When the head of the NASA / Harvard Origins of Life project gushed about finding Earth-like planets at a TED talk in Oxford, the Web went crazy over the prospects of making contact with E.T. or simply finding a new escape pod for humanity. The first problem was that those planets haven’t been found yet. And when they are found, as they likely will be, and then verified, that won’t mean we’ve found anything like oceans or an atmosphere at all.

“We [scientists] like to err on the side of caution,” John Geary, one of the Kepler co-investigators based at Harvard, told Motherboard on the phone back then. “Too often people get carried away and announce things that don’t hold up in the end, and it gives everybody a black eye. Things like cold fusion had an enormous splash in all kinds of media several years ago. It’s never been shown to have actually occurred."

Demon Wolf 4 Life

Still, sensationalists be damned or sent to Saturn’s darkest, most-alien-infested moon: this was a huge finding. A bacterium (specifically strain GFAJ-1 of the Halomonadaceae family of Gammaproteobacteria) taken from the bottom of famously inhospitable Mono Lake in California (and not just because it’s near Nevada) was grown in arsenic, not in phosphorus – the way every other living thing practically demands to be grown.

Now, nature can engineer substitutes for some other elements occasionally, but there has never until now been any replacement for the basic six elements: phosphorous, carbon, oxygen, nitrogen, hydrogen and sulfur.

Look how excited the lead researcher is, people.

Phosphorus is essential for forming the backbone of DNA and its chemical bonds: the temperature at which they break down, around 320 Fahrenheit, is considered the high-temperature limit for anything living. Arsenic meanwhile is typically toxic. It shares many of the chemical properties of phosphorous, which allows it to sneak into a cell’s machinery and messes everything up. Steven Benner, distinguished fellow, Foundation for Applied Molecular Evolution, Gainesville, Fla., called arsenic a “demon wolf.”

The XKCD take.

“If something here on Earth can do something so unexpected, what else can life do that we haven’t seen yet?” asked Wolfe-Simon, who is kind of a female biologist version of Carl Sagan.

The finding means two things: when looking for life on other planets, we should not be ignoring phosphorus-poor arsenic-rich environments. And this could for instance mean that other kinds of substitutions are possible (already, we know a Trilobite uses a different metal for its blood than Iron, for instance), like the substitution of silicon for carbon. Ni hao, Singularity.

The Meme is Old

At a conference in 2006, Dr. Wolfe-Simon dared to suggest that an organism that could cope with some arsenic might have incorporated arsenic instead of phosphorus into its diet. In a 2008 paper in The International Journal of Astrobiology she and Ariel Anbar and Paul Davies, both of Arizona State University, predicted the existence of arsenic-loving life forms. In a 2008 Science article, researchers discovered that arsenic could fuel photosynthesis in microbes found in Mono Lake.

We hypothesize that ancient biochemical systems, analogous to but distinct from those known today, could have utilized arsenate in the equivalent biological role of phosphate. Organisms utilizing such “weird life” biochemical pathways may have supported a “shadow biosphere” at the time of the origin and early evolution of life on Earth or on other planets. Such organisms may even persist on Earth today, undetected, in unusual niches.

The question for biochemists and evolutionary biologists is what particular role arsenic played in evolution on Earth. Was it mixed in with phosphorous in the primordial soup, competing for a role in biological husbandry, or was arsenic part of a completely separate lineage of life?

“Is there either a stage in the origin of life in which arsenic is the key element for certain chemical activities instead of phosphorus,” asks Greg Laden, “or, more interestingly, can we find populations in one part of the ancient earth (as fossils, of course) of phosphorus based bacteria and other populations, in different geological regions, of arsenic-based bacteria, living contemporaneously?”

But No Smoking Gun

There is a catch of course: Despite this low life taste for arsenic, the authors of the paper also reported, GFAJ-1 grew much better when fed phosphorus, as if it were starving and desperate not to have to eat its lab-coat torturers’ diet of arsenic. Gerald Joyce, a chemist and molecular biologist at the Scripps Research Institute in La Jolla, Calif. said after reading the paper, “I was feeling sorry for the bugs.”

The microbes stuffed with arsenic came out all mutated, 60 percent larger than cells grown with phosphorus, and with large, empty internal spaces. And while researchers were able to conclude that arsenic atoms had taken hold in the microbe’s DNA as well as in other molecules within it, the experimenters have yet to provide what one chemist calls a “smoking gun” that there was arsenic in the backbone of working DNA.

Even if the finding wasn’t totally Earth- or Internet-shattering, it has smacked our idea of life upside its head. But if we’re so intent on listening for life on other planets, it’s not certain we’re hearing that, or other findings.

“Maybe we’ll be able to find E.T. now!” said Voytek, the Astrobiology Program director. “Because we have more information about what we might be looking for.”

See the whole press conference at NASA’s Youtube (50:00)

Related:
More Evidence For Mars As A Life-Cozy Planet
NASA Delivers Yet More Evidence that Earth Isn’t That Special