NASA finds extraterrestrial life??

[»SD>Big]

http://kottke.org/10/11/has-nasa-discovered-extraterrestrial-life

 

Has NASA discovered extraterrestrial life?

Here's

a curious press release from NASA:

 

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.

 

I did a little research on the news conference participants and found:

 

1. Pamela Conrad (a geobiologist) was the primary author of a 2009 paper on geology and life on Mars

 

2. Felisa Wolfe-Simon (an oceanographer) has written extensively on photosynthesis using arsenic recently (she worked on the team mentioned in this article)

 

3. Steven Benner (a biologist) is on the "Titan Team" at the Jet Propulsion Laboratory; they're looking at Titan (Saturn's largest moon) as an early-Earth-like chemical environment. This is likely related to the Cassini mission.

 

4. James Elser (an ecologist) is involved with a NASA-funded astrobiology program called Follow the Elements, which emphasizes looking at the chemistry of environments where life evolves (and not just looking at water or carbon or oxygen).

 

So, if I had to guess at what NASA is going to reveal on Thursday, I'd say that they've discovered arsenic on Titan and maybe even detected chemical evidence of bacteria utilizing it for photosynthesis (by following the elements). Or something like that. (thx, sippey)

 

By Jason Kottke • Nov 29, 2010 at 10:20 pm • biology NASA science space

[»jabjabjab]

Im still betting Europa has life under the ice...

[Cheese]

to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life.

 

to discuss an astrobiology finding that will impact the search

 

that will impact the search for evidence of

 

do you not read at all or what

[»SD>Big]

Discovered: a new form of life

NASA's astrobiology announcement is that

they've found a new kind of life that incorporates the normally toxic arsenic into its DNA.

 

Life like us uses a handful of basic elements in the majority of its biochemistry: carbon, hydrogen, oxygen, and nitrogen for the most part. But phosphorus is also a critical element in two major ways: it's used as the backbone of the long, spiral-shaped DNA and RNA molecules (think of it as the winding support structure for a spiral staircase and you'll get the picture), and it's part of the energy transport mechanism for cells in the form of ATP (adenosine triphosphate). Without it, our cells would literally not be able to reproduce, and we'd be dead anyway if it were gone. There are many other ways phosphorus is used as well, including in cell membranes, bones, and so on. It's a key element for all forms of life.

 

[...]

 

Amazingly, using radioisotope-tagged molecules containing arsenic, they were able to find that the microbes incorporated the arsenic into their very DNA! It's hard to stress how shocking this is; as I understand it, saying something like that to a microbiologist without evidence would've had them slowly backing away from you and looking for weapons or an escape route.

 

I guessed wrong about what NASA was set to announce today, but the actual announcement is much more interesting than the mere discovery of extraterrestrial life. Aliens are inevitable -- we're going to find them sooner or later -- but a new kind of DNA, that's not something that happens every day. Exciting! (thx, jon)

 

By Jason Kottke • Dec 2, 2010 at 02:27 pm • biology NASA science

[007paulwall]

omg omg omg so amazing omg omg cant wait to see what happens next

[Cheese]

NASA's astrobiology announcement is that they've found a new kind of life that incorporates the normally toxic arsenic into its DNA.

 

on earth, a few many months ago

[Samapico]

We are thinking of it the wrong way... the Earth is not perfect for us, we are perfect for the Earth. Meaning, life can adapt itself to whatever environment. We have no idea what "aliens" could look like (if they could even look like anything...) .......... and......... and... wherever I was going with this, I'm sure it made sense.

[Dr Brain]

http://xkcd.com/829/

[»SD>Big]

i lol'd

[Aileron]

This discovery is actually something very profound though. Keep in mind that prior to the arsenic bacteria, Primordial Soup Theory stated that at some point in pre-history, life was created out of volatile chemical reactions. We've yet to fully explain it. We know where and when all the ingredients were in the same place at the same time, and we know the result, but we really don't understand the process, nor can we replicate it laboratory settings.

 

It was something incredibly improbable, and now we know that it happened in Earth's history not once, but at least twice, which in turn implies that it can't be a one in a billion occurrence. This makes the possibility of extraterrestrial life, even when you confine your definition to preclude other chemical combinations.

 

 

As for what aliens would look like, atleast by Discovery Channel Biology you'd be surprised how human-like an alien organism would have to be if you stipulate that they would be intelligent and capable of creating tools when you factor in 'survival costs'. The more complex an organism is, the longer it takes for it to reach maturity. If an organism spends too much of its life cycle in infancy, it can't survive. Now, keep in mind that humans need a decade and a half to reach biological maturity, which is an extremely long time frame on Earth's biosphere and is longer than most animal's entire lifespan. For that effort, we have superior intelligence, and frankly not much else. Most of the other mammals on earth are physically stronger, faster, and have better senses. We are essentially the bare minimum in terms of intelligent toolmakers, and even then we have a much higher survival cost relative to our competition.

 

The thing is, even on an alien planet, any intelligent life would have to compete against non-intelligent life, and survival costs will be a factor. Because of survival costs, any intelligent toolmaker would have to also be a 'bare minimum', which would ultimately make them relatively similar to us in a lot of ways.

[»Purge]

It was something incredibly improbable, and now we know that it happened in Earth's history not once, but at least twice, which in turn implies that it can't be a one in a billion occurrence.

This is an incorrect explanation, and you can thank the media for spinning things out of proportion.

 

What the experiment actually yields -- and this is indeed profound -- is that there is an organism inhabiting Earth that is capable of incorporating the compound arsenate into its nucleotides instead of the compound phosphate. However, this was only possible after giving it arsenate in a phosphate/arsenate mixture. Pure arsenate consumption occurred only after phosphate was removed from the mixture.

 

So, what you actually have here is an organism that prefers arsenate as its energy source, but will take up phosphate in the form of ATP just fine, too.

[Dav]

This is interesting, but not surprising given evolutions ability to adapt. Given Asnics properties are similar to phosphorus it is logical that organisms living in an arsenic rich environment may evolve to do this.

 

Incorporation of alternative elements of biomolecues is common. Selenium is frequently used in place of Sulphur. http://en.wikipedia.org/wiki/Selenomethionine

 

anyway the article has some controversy surrounding it http://rrresearch.blogspot.com/2010/12/arsenic-associated-bacteria-nasas.html.

 

I have to confess i have only skimmed over the press articles so far, I have a science subscription though so I will probably go find the actual paper when I get some spare time. It looks to melike they are saying the organism has evolved to tolerate high arsnic levels and encorporate it if it has to, but phosphorus is still the element of choice when it is available.

 

@ purge, for reference, phosphorous is usually taken up as inorganic phosphate rather then ATP. ATP is a very precious resource usually made and consumed as it is needed rather then produced in excess and released into the surroundings.

[»Purge]

o.0 Sounds like something I may have forgotten... I've been a year out of school just relaxing. Remind me of which inorganic phosphate this is?

[Dav]

http://en.wikipedia.org/wiki/Phosphate

[»Purge]

Oh I thought you were implying something totally different... Yeah, no way the bacterium uses ATP as its sole source. I wasn't thinking in context.