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from the not-very-useful—-they'll-just-chill-out dept.
We had two submissions on non-water-based life forms; the study and images are available at: https://cornell.box.com/azotosome
The search for extra-terrestrial life focuses quite heavily on the presence of liquid water. That's because all life on earth depends on water, using it as a medium for all cells, and an ingredient for many biological processes.
Is life without water possible? A chemical engineer and others at Cornell University devised a hypothetical model for life that could instead use liquid methane as its medium, opening more possibilities for simple life on Titan and on other cold moons and planets.
A new type of methane-based, oxygen-free life form that can metabolize and reproduce similar to life on Earth has been modeled by a team of Cornell University researchers.
http://phys.org/news/2015-02-life-saturn-moon-titan.html
(Score: 2, Insightful) by Anonymous Coward on Saturday February 28 2015, @04:13PM
Nothing like the Miller-Urey experiment has ever produced something as complicated as the phospholipid bilayer. Hopefully a simulation can estimate how likely it is for an "azotosome" to form in a hydrocarbon lake.
What if the azotosome cannot be synthesized by nature? Back to looking for warm watery planets.
(Score: 1) by khallow on Saturday February 28 2015, @07:15PM
What if the azotosome cannot be synthesized by nature?
It still might be synthesizeable by something which can be synthesized abiotically in a hydrocarbon lake.
(Score: 3, Interesting) by fritsd on Saturday February 28 2015, @07:35PM
While it's true that the Miller-Urey experiment didn't come alive and bite its caretakers, it was only a small flask. If you repeat it on a planetary scale you'll get a gain of more than ten orders of magnitude. (I dunno, how much bigger are the oceans compared to that bottle??) Also the timescale of the experiment was a few decades IIRC, so you can add 5 orders of magnitude and see what you can get in 1 million years. If those vesicles or what you call them are relatively stable then you'll get more of them over time upto a saturation point. If the inside of some of the vesicles causes them to be more stable, or to split into two vesicles, etc. then that pattern of organization endures even more easily.
Avogadro's number is 10^23, so even extremely small likelihoods of success in assembling RNA or an azotosome will occur randomly as long as you wait long enough and your planet is large enough to do the experiment in parallel.
Actually I'm talking nonsense here a bit, because of course Avogadro's number was already incorporated in the original experiment. But what if it was *almost* enough and needed just a boost of a factor million or so.
As molecules get larger, the "conformation space" of their internal angles also becomes more complex rapidly (curse of dimensionality) so you'll need more and more time for them to fold "properly" without help.
Existing biomolecules such as enzymes and DNA have extremely nifty schemes to change that near infinite conformation space to something like folding a T-shirt or unzipping a zipper, but they are the end-product of a very long evolution.
If you don't know much about biochemistry and you'd like to learn more about the fascinating stuff that can be done with self-replicating molecules such as DNA, read this: http://en.wikipedia.org/wiki/DNA_polymerase [wikipedia.org] (the pictures show that it would takes a lot of time and luck to assemble this enzyme from scratch :-) ), or this: http://en.wikipedia.org/wiki/Polymerase_chain_reaction [wikipedia.org]
(Score: 2) by Runaway1956 on Saturday February 28 2015, @07:58PM
I think that the underlying point of the article is, if/when we find extraterrestrial life, it may not be like life on earth.
The authors are looking at methane creatures, because that is the easiest alternative to imagine. But - they are still searching close to home.
What is to say that there must be an azotosome? What if it's unnecessary? What if, when we finally stand face-to-whatever with an alien life form, we don't even recognize it as life? It simply doesn't meet ANY of our expected criteria!
(Score: 0) by Anonymous Coward on Sunday March 01 2015, @12:25AM
I want it to be true, I'm just really skeptical. If the azotosome is viable, could it develop on Earth? Are we fracking azotosome life right now? Or does it require liquid methane oceans...
I think we are setting ourselves up to be disappointed when we scour the cold bodies and under-ice oceans of this solar system and find nothing. Chances are we will find life by finding an Earth-like atmosphere and vegetation on a nearby exoplanet using JWST or one of Hubble's next next successors. We know that many stars appear to have an exoplanet in the habitable zone, including red dwarf stars. We have a growing list of confirmed and candidate exoplanets. We just need a bigger scope.