Boost to Chances of Life on Europa? 57
Gavinsblog writes "New Scientist is reporting that scientists have found that electricity
is produced when aluminium bullets are fired into a block of ice. This raises
the chances of finding life on Europa, as eletrical shocks of this kind could
cause complex molecules to form. An electrifying discovery? :-)"
Title? (Score:5, Funny)
In the Netherlands... (Score:1)
Guns create life. (Score:1)
Elecrifying discovery (Score:5, Funny)
I'm shocked that someone would say that.
Re:Elecrifying discovery (Score:3, Funny)
Re:Elecrifying discovery (Score:1)
(Yeah it took me a sec to think that lame one up)
Re:Elecrifying discovery (Score:1)
Re:Elecrifying discovery (Score:1)
Re:Elecrifying discovery (Score:1)
Yeah, the're really amped.
Cause all you really need... (Score:2, Funny)
They should know what those yellow brown stains on the ice are... someone had a super biggulp on the way to europa and couldn't hold it!
All these worlds are yours except Europa... (Score:2, Funny)
Re:All these worlds are yours except Europa... (Score:1, Funny)
Except that the USSR didn't make it this long...
hrm (Score:4, Funny)
~GoRK
life on europa... (Score:1)
Just like humanity... (Score:5, Funny)
Over-hyping? (Score:5, Informative)
Even then, this is hardly ground-breaking. Electric sparks are not the only way to generate organics. Urey and Miller also showed that UV light can do the same thing. All you really need is a high-energy source to break up some bounds and allow new ones to form. Heck, even the particle radition in Jupiter's magnetosphere can probably do some of that. The UV flux is down by a factor of 27 from that at Earth (top of the atmosphere, now at the surface where ozone and other molecules have attenuated it), but I'd bet you can provide more activation energy that way than with little electric shocks from impacts.
That said, it's a damn cool result without all the "Life on Europa" hype.
Re:Over-hyping? (Score:5, Insightful)
Take this example of mine: I work on an enzyme that I have to store some samples of at -80 C for later experiments. I found that if it had been stored at -80 C for a long time (1-2 years) the enzyme is inactivated, but this is not due to the freezing process itself so some chemical change is occuring in ice at -80 C over a months to years timeframe. Pretty "cool" eh?
Re:Over-hyping? (Score:3, Interesting)
I'm not sure you'll see heat build-up, though. The sparks probably won't produce much energy, certainly less than the thermal energy produced directly by the impact. And that diffuses away fairly quickly at these temperatures. I forget the the exact timescales, but recall that passing into and out of Jupiter's shadow is enough time for the moons to heat and cool significantly. That timescale is of order a day or few.
That damn dog! (Score:3, Funny)
Newer images reveal evidence that these stains may have been left after a recent pass of Pluto.
Re:That damn dog! (Score:2, Insightful)
Doing "research" (Score:1, Offtopic)
Even if Ice Lord Fist came from space.
Haha, so you finally found us (Score:1)
Miller-Urey is pointless (Score:4, Insightful)
Additionally, they only made a tiny fraction of the amino acids necessary for life. Those that were made were racemic, while life is universally homochiral in proteins (the tiny number of exceptions are in things like bacterial cell walls).
And the sludge they did produce was mostly tar (a term used by organic chemists to mean the sludge left behind when you can't extract anything useful from it). In fact it was 85% tar, 13.0% carboxylic acids (many of which would destroy life before it could get started), 1.05% glycine (the simplest amino acid) and 0.85% alanine (the second simplest amino acid). There were also trace amounts of glutamic, aspartic, valine, leucine, serine, proline, and treonine.
If you want to understand the problems with the chemistry of the origin of life, there's a good paper [cremesti.com] that's pretty readable for those with a bit of exposure to chemistry.
Re:Miller-Urey is pointless (Score:5, Interesting)
The point of these experiments is not to reproduce the early-Earth conditions exactly. We still don't know what those are. But the fact that such a wide variety of conditions produce organics is an indication that the goop is easy to form and probably did so on the early-Earth, regardless of the conditions.
(Your point about the chirality of the amino acids is a red herring. There is no reason to think that life was formed in a soup of only one chirality. All we know is that somehow life on Earth has evolved to use only one of those. It isn't hard to imagine that one or the other might have a slight advantage or even that life had to - at some early stage - chose just one and use it. Dealing with both L and D forms all the time would probably require a lot more effort than it's worth.)
Re:Miller-Urey is pointless (Score:3, Insightful)
It's a nice hand wave to sayYet you are attributing purpose to "life", as when you say "chose". Yet evolution is supposed to happen by random changes, not by direction.
And you point about creating organics is quite true, heat carbon, hydrogen, and oxygen under a bit of pressure and you'll get all kinds of things. But those are immersed in a toxic soup that would annihilate any peptide bonds.
Re:Miller-Urey is pointless (Score:1)
Generally it can be said about every "feature" of life that at some point in the past a choice was made by a series of random happen stances and confining conditions, which gave one solution or a small set of solution an advantage to win out over others.
No external hand need to be implied when using the word "choice".
---
Statically some would escape or resist the "toxic soup" as a result of interaction with others. They would accumulate over time allowing them to become potential building blocks.
Resistance is futile (Score:1)
I think you meant to say "statistically", and no, they don't. The toxic soup kills them, no matter how they interact. That's why it's called "toxic".
Re:Miller-Urey is pointless (Score:4, Insightful)
Once life randomly tips chirality away from 50/50 it drives it all the way one way or the other. Life that happens to use more of one type will evolve to manufacture more of that type. That type falls back into the enviornment and makes that type more common as "food".
It's sort of like VHS vs Betamax
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Re:Miller-Urey is pointless (Score:5, Insightful)
Controversial? Certainly. Pointless? Hardly.
First of all, your criticism of M-U's experimental conditions is straw-man logic - you damn them for not using free O2, then promptly turn around and demonstrate the unlikeliness of free O2 in the primordial atmosphere - as you point out, it would have oxidized practically everything in reach. Despite recent evidence that the early Earth's atmosphere wasn't completly reductant after all, there's still little reason to think that free O2 in significant amounts was present before life came along. Also, please note that a typical electric discharge emits more than a little ultraviolet. Not nearly as much as solar UV flux, but let's be reasonable - their apparatus didn't simulate asteroid impacts, lava flows, or full-scale lightning strikes either.
Second: Okay, fine - a week-long experiment intended to loosely approximate conditions on Earth over the first billion-odd years of its existence didn't end with lizards crawling out of the flask. The significance of M-U isn't that it generated every chemical necessary for life, but that it managed to generate any at all. (Even if you factor in the amino acids found in meteorites, etc., those amino acids came into being somehow.) Tell you what - I'll start up an M-U-like experiment, let it run for a few million years, and let you know what happens.
Third: I rather hope Cremesti didn't pull better than a C-minus on that paper. It continually amazes me how creationists (one of which I am not necessarily assuming Cremesti is) continue to hammer away at the random-chance argument of life's origin / evolution, when I don't think there's a single evolutionary biologist out there who accepts it. Darwin didn't accept it. (It's rather a tickle to read about how this theory, such as it is, was demolished by computer analysis; with what was essentially a primordial ecological simulator. Run on "high-speed computers". In 1966. Project headed by Dr. Forbin [imdb.com], I assume.)
The rest of the paper is crap, full of bandwagon assertions ("Many authors believe..."...so it's obviously true. Would've been nice if he'd cited some of them.) and silliness like invoking the Second Law of Thermodynamics to show that "...[chemical evolution] will not occur in isolated or closed systems near equilibrium" when it's arguable that none of these conditions obtain even on a planetary scale, and glaringly obvious that they don't on a local scale. (Fun experiment: Hold up a tall metal pole in the middle of a thunderstorm, and determine how long your local environment remains in equilibrium.)
When we research things that occur on a time/space scale as grand as this, imho one of the biggest obstacles is the limits of human imagination. Can you picture - really grasp emotionally - intervals longer than your own lifetime? Or distances further than those you've actually traveled? I disagree with Cremesti in that I do not believe that chemical evolution is not falsifiable. I'm not so sure that it can be done by human beings, at least not for a very long time to come. Given a problem with thousands of variables, many unknown, whose domain is an entire planet (or many planets, if you accept panspermia) and hundreds of millions of years, can even the most knowledgable scientist state with confidence that any plausible event did or did not happen? No matter how fast the computer or how sophisticated the methods, is it possible to analyze such a problem and get results better than a coin flip? Again, not now, and imho not for a long time to come. The value of M-U is not that it showed the mechanism by which life originated on Earth, but that it showed a part of a plausible mechanism.
The first step is always important, even if it turns out to be in the wrong direction.
DDB (having a slow day at work)
Re:Miller-Urey is pointless (Score:1)
I note you attack Cremesti for not exhaustively footnoting, I agree that's a deficiency in his work which, if I knew him, I would point out to him. However my point in providing the link is to look at the simple science he does point out. Such as the half-lives of the prebiotic components.
Your attempt to use vast times and distances to rationalize how something improbable could happen would make sense, if it was less improbable that it is. If you look at just how like is it for one 450 residue protein to have just the correct chirality at all its chiral positions (leave off 8% as the average amount of glycine in a protein), you have 2^(450*.92) = 2^(414) = 10^124.
There have been only 10^18 seconds since the big bang (if you believe in that model). The universe is only 10^28 inches across or so. 10^124 is staggeringly larger than those numbers, so you're still stuck with impossible odds to just get the chirality right on just one protein. Never mind getting the amino acid sequences anywhere near correct, or folding it properly, or having it in an environment of proper salinity, pKa, temperature, dissolved gasses, etc.
Re:Miller-Urey is pointless (Score:5, Informative)
Such as the atmosphere being C02, CH4, H20, NH3 with no free 02. At our distance from the sun, this atmosphere is absurd. Why? Because the hard UV that would be coming in without any ozone layer (no O2 in the atmosphere, no ozone layer) would dissociate the NH3 rapidly into N2 and H2, as it would CH4 into more complex oils.
Yeah, except that H2O, CH4, and NH3 block UV light. CH4 is a very stable element. It's methane. It is in the atmopheres of several planets. Ammonia is also stable. It can only be cracked into H2 and N2 with very high temperature furnaces, typically.
And the sludge they did produce was mostly tar (a term used by organic chemists to mean the sludge left behind when you can't extract anything useful from it). In fact it was 85% tar, 13.0% carboxylic acids (many of which would destroy life before it could get started), 1.05% glycine (the simplest amino acid) and 0.85% alanine (the second simplest amino acid). There were also trace amounts of glutamic, aspartic, valine, leucine, serine, proline, and treonine.
Laboratory simulations of primitive earth have produced all 20 amino acids used by life, as well as ATP and the 4 dna bases. If you have those 20 amino acids, you can form any protein in existence.
Of course you need to be able form something with all of those chemicals. Have you heard of protocells? These are structures that can be formed very easily with a few amino acids. In fact, if you have a few chemicals, you can make them quite easily at home. Anyway, they don't have DNA, but are capable of budding, metabolizing, using ATP, and non-darwinian chemical evolution.
As for your link to to Cremesti. That's a well known very biased creationist site. And that essay took quotes by many scientists way out of context. The classic creationist tactic of making debate about the specifics of a theory sound like the scientist is attacking the entire general theory.
Re:Miller-Urey is pointless (Score:1)
And while perhaps you could stretch to say NH3 blocks UV light, it actually absorbs it and is dissociated by it. Personally I would not call that blocking. If I'm getting shot at, I want a barrier that blocks the bullets, not one destroyed by the bullets.
Of course CH4 is stable; it's entropically very happy. Four nice covalent SP3 bonds in a pretty tetrahedron. Yet add energy and it will dissociate, similarly to NH3 (which is very analogous even in its orbital hybridization characteristics).
If you check Miller's later work, you'll see he discusses the fact that the experiment had to be stopped after a few days, or the entire experiment just turned into unresolvable, unextractable brown goo.
Protocells are not an answer for abiogenesis; unless something can reproduce accurately, it cannot evolve. Without near-perfect replication, evolution cannot happen. Only when you have a tiny (not zero) amount of errors in replication can one generation inherit the beneficial mutation of the previous generation. Protocells have no replication control mechanism, budding of one to another is uncontrolled and will result in a random partitioning of the contents. This is not fodder for natural selection, as the "descendants" are unlike the "parents", and without natural selection, evolution is not in the picture. So protocells are no more useful in explaining abiogenesis than the Miller-Urey experiments.
Ingenious! (Score:2)
They've Found It (Score:1)
Yes, those yellow-brown stains on the ice -- they've found the Chicago Blackhawks' secret training facility.
So now all we need is... (Score:2, Funny)
I bet (Score:3, Funny)
I bet you lay awake all night thinking of that punchline before you submitted this story, didn't you?
Re:I bet (Score:1)
They should go for the obvious. (Score:1)
Lemme get this straight ... (Score:1)
hmmm
AAAAAHHH!!!!</panic>
It's okay, though
How shocking is this? (Score:1)
"A lander may be sent to the surface of the Europa to look for organic matter." "The Europa" is right out.
Think an editor or stopped before he or she got to the end?
Aluminum block != asteroid (Score:2, Interesting)
Repeat after me. (Score:3, Insightful)
Firing bullets into ice does not increase the chances of finding life on Europa.
In fact, the only thing that increases the possibility of life being found anywhere, is finding life somewhere. It doesn't matter how many stars there are, or planets, or planets with water. One data point (Earth), that we are the product of, does not count.. Untill we can look at X number of planets / Y number with life, we know zero about the chances of finding life.
Re:Repeat after me. (Score:2)
My point is is that there is no probability at all, we simply don't know how rare (or common) life is, so all calculations are suspect. (20^19+1293) * 0 still equals 0.
I want to find life elsewhere as much as anyone. I'm down with my tax dollars being used to look. But any calculation of lifes chances falls victim to the anthomorpic trap. Think of it this way; If life did _not_ exist on Earth, how does that change the chances of finding life on Europa?