Dec
02
2010

Life not as we know it: NASA discovers aliens on Earth.

The shores of the alien world: Mono Lake, California, Earth.
The shores of the alien world: Mono Lake, California, Earth.Courtesy Eeek
Big news from NASA today, y'all.

NASA scientists are holding a conference at 2:00 EST today, and I hate to spoil the surprise, but word on the street is that they've discovered life on the planet Earth. Ah... but it's not what you think—word is that they've discovered life that's really different from everything else here.

Last year, I posted about the theory that this sort of thing might exist, but it wasn't until now that it has actually been discovered. Here's the gist: bacteria living in the mud of weirdo Mono Lake have been found to use arsenic as a building block of their bodies. That may not sound like much, but, if it's true, it would mean that these bacteria are different than every other living thing on this planet. Everything else that lives on this planet is made of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. These creatures use arsenic instead of phosphorous.

Aside from being super cool and different, the discovery suggests that if life can exist in ways we didn't think was possible, it can exist in places we didn't think life was possible. Like other planets and moons in our own solar system.

More details after the conference, hopefully.

Your Comments, Thoughts, Questions, Ideas

JGordon's picture
JGordon says:

Here's NASA's press release about the discovery: Nasa-Funded Research Discovers Life Build With Toxic Chemical.

posted on Thu, 12/02/2010 - 3:43pm
bryan kennedy's picture

Sometimes it's fun to read the actual scientific journal paper, even if it is full of some rather complex chemical equations. Fortunately this one is available for free online.

posted on Thu, 12/02/2010 - 4:10pm
mdr's picture
mdr says:

U of M-Morris biologist PZ Myers isn't as impressed by this "startling news" as NASA wants everyone to be.

"Scientists started out the project with extremophile bacteria from Mono Lake in California. This is not a pleasant place for most living creatures: it's an alkali lake with a pH of close to 10, and it also has high concentrations of arsenic (high being about 200 µM) dissolved in it. The bacteria living there were already adapted to tolerate the presence of arsenic, and the mechanism of that would be really interesting to know…but this work didn't address that."

"...So what does it all mean? It means that researchers have found that some earthly bacteria that live in literally poisonous environments are adapted to find the presence of arsenic dramatically less lethal, and that they can even incorporate arsenic into their routine, familiar chemistry."

"...It does say that life can survive in a surprisingly broad range of conditions, but we already knew that."

You can read Professor Myers' whole take on it at his Pharyngula website.

posted on Thu, 12/02/2010 - 5:54pm
Liza's picture
Liza says:

I read PZ's post, too, and I honed in on a different quote:

"What they also found, and this is the cool part, is that they incorporated the arsenate into familiar compounds. DNA has a backbone of sugars linked together by phosphate bonds, for instance; in these baceria, some of those phosphates were replaced by arsenate. Some amino acids, serine, tyrosine, and threonine, normally contain phosphates, and arsenate was substituted there, too. What this tells us is that the machinery of these cells is tolerant enough of the differences between phosphate and arsenate that it can keep on working to some degree no matter which one is present."

That is cool, and I think it does make these bacteria different than any other form of life so-far described. Maybe we shouldn't be surprised that it's possible. After all, this experiment has been running for a while, and, as MDR points out, they did deliberately select bacteria from one of the most inhospitable environments we can imagine. But...so far, no other form of life can do what these guys can do. And it means we have to rethink, a bit, our chemical definition of life. That's amazing.

posted on Thu, 12/02/2010 - 6:00pm
bryan kennedy's picture

Gene just emailed me an interesting like on Slate:
"This Paper Should Not Have Been Published"

Several scientists seem to think that actual scientific process used in this research was spurious and doesn't convince them that the NASA scientists found arsenic based bacteria. It's interesting to see the discussion around this scientific "discovery?" in more far-flung places like Gawker and Slate. Yay science talk.

posted on Wed, 12/08/2010 - 11:55am
JGordon's picture
JGordon says:

Yeah, it's cool that people are interested enough in this that the discussion is getting press.

I wish that were the case with more research—I saw this dismaying project the other day, which might come from good intentions (I hope), but it misrepresents research, and seems to encourage people to develop similarly reductive and dismissive attitudes.

On a side note, I always think it's funny how sort of... nasty, I guess, scientists can be. Not that they shouldn't be questioning each other's research—they absolutely should—but the way some of those quotes come across, you'd think that the NASA scientists were doing their experiments drunk in a bathtub, while playing hooky from freshman biology. Oh, scientific community... y'all are people too, I guess.

posted on Wed, 12/08/2010 - 12:12pm

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