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Space Science

Meteorites May Have Delivered Seeds of Life On Earth 277

Posted by Zonk
from the thanks-for-the-lift dept.
esocid writes "At the national meeting of the American Chemical Society, scientists presented evidence today that desert heat, a little water, and meteorite impacts may have been enough to cook up one of the first prerequisites for life. The result of that brew could be the dominance of "left-handed" amino acids, the building blocks of life on this planet. Chains of amino acids make up the protein found in people, plants, and all other forms of life on Earth. There are two orientations of amino acids, left and right, which mirror each other in the same way your hands do. These amino acids "seeds" formed in interstellar space, possibly on asteroids as they careened through space. At the outset, they have equal amounts of left and right-handed amino acids. But as these rocks soar past neutron stars, their light rays trigger the selective destruction of one form of amino acid."
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Meteorites May Have Delivered Seeds of Life On Earth

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  • by eldavojohn (898314) * <eldavojohn@nOsPam.gmail.com> on Sunday April 06, 2008 @10:35PM (#22985030) Journal
    We discussed something similar to this here [slashdot.org] where they found organic molecules in a Canadian meteor.
    • by EmbeddedJanitor (597831) on Monday April 07, 2008 @01:15AM (#22985896)
      Where did those amino acids come from?
      • Re: (Score:3, Insightful)

        This is just another possible piece in the jigsaw puzzle.

        It's a bit churlish to say this doesn't explain anything. It just doesn't explain everything. This early on in the game there are still lots of threads to pick up in the story. When you watch a murder mystery, do you start complaining after a couple of scenes because they haven't found the murderer yet? Or perhaps you're too used to columbo...

        give them a chance to figure it out, it's not like the emergence of life is some kind of trivial problem t

    • by MrNaz (730548) * on Monday April 07, 2008 @01:18AM (#22985916) Homepage
      The idea that nucleic acids and other organic building blocks were delivered to Earth from a meteor is not new. In fact, I remember reading about that in a space book when I was 5.

      Personally, I think that whether or not the "seeds of life" originated here or came here on a meteor is a stupid idea, as it's not where they came from that is even remotely interesting, but how they came to be in the first place. If they originated here, then an asteroid impact may have scattered them elsewhere, and there may be other bewildered life forms on other planets wondering where they came from, or vice versa. What difference does it make?

      What I want to know is how complex organic molecules were formed into self-organising, self-replicating structures. Bigfoot is not the missing link. How we got to elemental material spewed out from a supernova to DNA, *that's* the missing link.
      • Re: (Score:3, Insightful)

        by MrNaz (730548) *
        "How we got to elemental material spewed out from a supernova to DNA"
        Should read:
        "How we got from elemental material spewed out from a supernova to DNA"

        I'd say I didn't preview, but that excuse no longer exists. I guess I'm just a tard :(
      • by ampathee (682788) on Monday April 07, 2008 @03:40AM (#22986446)

        What I want to know is how complex organic molecules were formed into self-organising, self-replicating structures. Bigfoot is not the missing link. How we got to elemental material spewed out from a supernova to DNA, *that's* the missing link.
        For the answer, I recommend you read "The Selfish Gene" by Richard Dawkins. It's a very well written and interesting book which answers that exact question. I just finished it a couple of months ago.
        • by MrNaz (730548) * on Monday April 07, 2008 @06:48AM (#22987080) Homepage
          No, that book is an evolution (pardon the pun) of the theory of evolution. It deals with what happened (in RD's view) *after* the avalanche of life had been triggered.

          What I was asking was, what was the first snowflake that started that avalanche. Wake me up when people have started caring about that, coz I don't see much discourse on that subject in the scientific media.
          • by dreamchaser (49529)
            I don't see much discourse on that subject in the scientific media.

            You mean in popular scientific media. The origin of the first life is a very hot topic amongst those in biological disciplines, and there are several competing theories. I suggest you start with a bit of reading on Abiogenesis [wikipedia.org] on Wikipedia. You'll find quite a few relevant citations as well as a discussion of past and current models.
        • While I in general will agree with most praise for The Selfish Gene - it is a very nice work - it doesn't cover abiogenesis in any firm fashion. Dawkins has repeatedly stated that we don't know that missing link, and he's purposefully used different hypotheses in different books, in order to not give the impression that he endorse one particular hypothesis as true.

          Eivind.

      • by 24-bit Voxel (672674) on Monday April 07, 2008 @03:59AM (#22986502) Journal
        Maybe complex organic molecules form into self-organising self replicating structures BECAUSE they were delivered from elsewhere. The two need not be mutually exclusive.

        What if the "seeds" of life require foreign interference to mutate into life. I don't understand how we can evaluate a missing link if we don't know where all the components came from. The Earth could have been an unfertilized egg waiting to be inseminated. For that reason how they came to be is just as interesting as where they came from especially if they are intertwined.

        Imagine the odds that would have to be overcome if it takes a specific type of meteor to react with a specific type of dead planet to make life. If that is true the odds of the right elements being present in both cases could be so high that they could be conceivably called divine. It would be pretty funny as well if the chain reaction took 7 days.
      • Re: (Score:2, Interesting)

        by BRUTICUS (325520)
        I disagree, I find it very interesting. The visual analogy of a sperm fertilizing an egg replicated in life being fertilized on a planet? Beautiful.
        • by MrNaz (730548) *
          Beautiful metaphor is not the same as useful scientific proposition. If you find the asteroid & planet metaphor for sperm and egg to be aesthetically pleasing, so be it, but until it has some useful empirical meaning then call that metaphor what it is: religious imagery.
      • I completely agree, and would like to go on to say that amino acids are fairly simple if you think about it. While not complex in themselves they lend themselves to building complex things by how they are organized. Like MrNaz asks, it's not how they got here or even how the acids formed in the first place, it's how we went from amino acids to life that's the real question. Once we can focus on that, then perhaps we'll start to find possible answers.
  • by Anonymous Coward on Sunday April 06, 2008 @10:38PM (#22985050)
    It means that there is only a 50% chance we are edible for aliens!
    • Re: (Score:2, Funny)

      by Anonymous Coward
      The better news is that we're 100% edible to each other. Now if you'll excuse me, I'm gonna go finish reading my copy of How to Serve Man.
  • God vs. ...that. (Score:4, Insightful)

    by 75th Trombone (581309) * on Sunday April 06, 2008 @10:41PM (#22985068) Homepage Journal
    I have a feeling a creation vs. evolution flamewar is about to start. Creationists will be creationists, but everyone else just think for a second:

    If you were an average joe, not even a stupid joe but an average joe, which honestly sounds more convincing: 1) A supreme being did it, or 2) blah blah amino acids blah blah meteorites blah blah neutron star light rays blah blah?

    So y'know, take it easy on the creationists. They may not understand how science works, but when faced with an article like this, can you really blame them?
    • by Dada Vinci (1222822) on Sunday April 06, 2008 @10:46PM (#22985122)
      Well, you've actually hit on one of the main creationist talking points -- "what are the odds that we'd all have left-handed amino acids, instead of a random mix that wouldn't work?" I'd be intersted to hear how they respond. I'd imagine with the same response as always (God put it here), but who knows. A good theory of why left-handeness is preferred (at least among amino acids) is a pretty big deal.
      • Re:God vs. ...that. (Score:4, Informative)

        by WaltBusterkeys (1156557) on Sunday April 06, 2008 @11:14PM (#22985296)
        I'm trying to understand why the above is a troll. This is a big deal theory.
      • Re: (Score:3, Interesting)

        by the cheong (1053282)
        "what are the odds that we'd all have left-handed amino acids..."

        In econometrics, I learned this to be "Sample Selection Bias". The odds that we'd all have left-handed amino acids might be nill. However, the odds that we'd all have left-handed amino acids GIVEN that we've become conscious beings able to analyze such a thing?

        I mean, maybe there WERE a lot of failures. But somewhere in the universe, ONE worked. And BECAUSE we worked, we're able to wonder about it.
      • by TheNarrator (200498) on Monday April 07, 2008 @01:11AM (#22985872)
        Seems there's a lot of people out there who think that this or that scientific discovery will make all the creationists wake up and finally abandon creationism. Not going to happen. You just can't reason somebody out of something they weren't reasoned into in the first place.
        • Re: (Score:3, Interesting)

          by Tiberius_Fel (770739)
          I don't think that it's true that you cannot reason someone out of something they were not reasoned into. I was raised to believe in a certain religion but I was talked out of it (not all at once, mind you). I guess a more accurate thing would be to say that the problem is that these people aren't susceptible to reason in the first place...
      • Re: (Score:2, Interesting)

        by jdagius (589920)
        >> I'd be interested to hear how they respond.

        I view the the creation story in Genesis as a literary fable, but believe that the creation and evolution of life is the result of an "intelligent design". Yes, parts of it appear to behave randomly, but all life is "derived" (using a software design metaphore) from abstract "foundation classes" i.e. sets of universal templates and behavioral principles, that permit life to be instantianted and elaborated with form to match needed functionality.

        So,
      • Re: (Score:3, Informative)

        by db32 (862117)
        The main creationist talking point stems from a piss poor understanding of math and probability as well. My favorite explanation was actually Douglas Adams. It had to do with since a point has 0 dimensions there is an infinite number of points on a dart board. The tip of a dart represents a single point. When you throw the dart at the dart board and you calculate the probability of the dart hitting any specific point you arrive at 1 / (infinite) and it becomes impossible to hit any specific point on a d
    • by khallow (566160) on Sunday April 06, 2008 @10:54PM (#22985178)

      They may not understand how science works, but when faced with an article like this, can you really blame them?
      Poorly written news articles don't excuse flawed thinking. One shouldn't depend on shallow news stories or vague religious texts for explanations of the physical world.
      • no one is pretending this isn't speculation.

        This is food for thought. It's the interesting banter to provide a bit of context and fun. It's like the crossword puzzle or the Garden Tips in your local newspaper.

        So ease off a bit... no one is depending on this article for anything but a bit of fun thinking. And who knows, they could very well be right! so what if it's very unlikely? Common sense, after all, tells us the Earth is flat.
        • by jc42 (318812)
          Common sense, after all, tells us the Earth is flat.

          Maybe if you live in Kansas. I grew up in the Seattle area, where most of the horizon (when it's clear enough to see that far ;-) is taken up by a lot of very bumpy mountains. Now I live near Boston, which is generally a bit flatter, but I live on an obvious hill and the view out my windows shows several other very obvious hills.

          I've also spent time along the edge of oceans or large lakes, where the way that boats disappear over the horizon from the bott
    • Re: (Score:2, Insightful)

      by ScrewMaster (602015)
      So y'know, take it easy on the creationists. They may not understand how science works, but when faced with an article like this, can you really blame them?

      Really, you should have gotten a +1 Funny not a Troll mod. Fact is, those are exactly the kind of people that bring down civilizations, so going easy on them isn't an option. So far as not understanding science ... well, it's not my fault they didn't pay attention in 7th grade science class. If they don't understand what they're talking about they sho
      • well, it's not my fault they didn't pay attention in 7th grade science class.
        How do you know that? Depending on the school they went to, creationism may have been taught to them in their 7th grade science class. It's often difficult to get someone to go against what they were told for the first 18 years of their lives.
    • by 0xdeadbeef (28836) on Sunday April 06, 2008 @11:37PM (#22985432) Homepage Journal
      "A cosmic Jewish Zombie who was his own father can make you live forever if you symbolically eat his flesh and telepathically tell him you accept him as your master, so he can remove an evil force from your soul that is present in humanity because a rib-woman was convinced by a talking snake to eat from a magical tree."

      vs.

      "A rock from space covered in particular chemicals crashed into the earth three billion years ago, and through a process of self-replication and environmental pressure, these chemicals produced more complex molecular structures, leading to life as we know it."

      Yeah, Christianity is so much more plausible.
      • Christianity is a minority belief on this planet, a large minority, but still...

        Personally, I think it is turtles. Yup, all the way down [wikipedia.org].

        • by mcvos (645701)

          Christianity is a minority belief on this planet, a large minority, but still...

          Since there are so many of them, all belief systems (including atheism and agnosticism) are minority beliefs, but if I'm not mistaken, Christianity is the biggest minority.

          I thought I once read that Hinduism or Buddhism had close to a billion followers, and considering the populations of India and China, you'd expect them to be pretty big, but according to Wikipedia [wikipedia.org], they're a lot smaller than Islam.

      • by pkphilip (6861)
        Let the scientists come up with a *single* unicellular life form using any/all these amino acids by *deliberate* and *guided* methods in a *controlled environment* within a *lab* using all the scientific resources currently available, and I will start believing that it is indeed possible for life to form from a sea of amino acids and other organic material.

        Anything that can be created by evolution can be created by deliberate engineering. If not, I would like to hear why not?

        Till then if I choose to believe
        • by pkphilip (6861)
          To continue - taking any organism and replacing its DNA or changing its DNA is NOT the same as creating an organism in the first place.
        • Re: (Score:2, Insightful)

          by dookiesan (600840)
          You may as well not believe in plate techtonics because we can't yet move a mountain. We will accomplish that goal of artificial life in a lot less than a billion years if we don't go extinct before then.

          Even hard proof that we were derived from random evolution should not shake anyone's faith in God.

          A person may claim to see colors and hear sounds and have other subjective experiences. The more we learn about the brain the less need there is for any of these subjective things to exist. Science is explai
          • Re: (Score:3, Insightful)

            by pkphilip (6861)

            Even hard proof that we were derived from random evolution should not shake anyone's faith in God.

            Before we can arrive at any *hard proof* of evolution, we will first need to know what it takes to create a self-replicating organism in the first place. We are no where near knowing the different steps it takes to deliberately create a living unicellular organism.

            When we don't even know this, we cannot reasonably postulate the different evolutionary stages required to create this same organism.

            Anything that can come about by evolution can be deliberately engineered. If not, why not?

            • by Guido von Guido (548827) on Monday April 07, 2008 @08:12AM (#22987662)
              "Before we can arrive at any *hard proof* of evolution, we will first need to know what it takes to create a self-replicating organism in the first place."

              Evolution (and the evidence for it) does not depend (logically or otherwise) on the origin of life. It doesn't really matter if the first self-replicating organism developed in a pool on the beach or in a deep-sea thermal vent, if it came from a meteorite from somewhere else, or if God poofed it into existence.

              To suggest that evolution depends on this in any way is just moving the goal posts around.
        • by dibblda (882455) on Monday April 07, 2008 @01:59AM (#22986068)
          WEll..... try here: http://objectiveministries.org/creation/sciencefair.html [objectiveministries.org] 1st Place: "Life Doesn't Come From Non-Life" Patricia Lewis (grade 8) did an experiment to see if life can evolve from non-life. Patricia placed all the non-living ingredients of life - carbon (a charcoal briquet), purified water, and assorted minerals (a multi-vitamin) - into a sealed glass jar. The jar was left undisturbed, being exposed only to sunlight, for three weeks. (Patricia also prayed to God not to do anything miraculous during the course of the experiment, so as not to disqualify the findings.) No life evolved. This shows that life cannot come from non-life through natural processes. 2nd Place: "Women Were Designed For Homemaking" Jonathan Goode (grade 7) applied findings from many fields of science to support his conclusion that God designed women for homemaking: physics shows that women have a lower center of gravity than men, making them more suited to carrying groceries and laundry baskets; biology shows that women were designed to carry un-born babies in their wombs and to feed born babies milk, making them the natural choice for child rearing; social sciences show that the wages for women workers are lower than for normal workers, meaning that they are unable to work as well and thus earn equal pay; and exegetics shows that God created Eve as a companion for Adam, not as a co-worker.
          • by Alsee (515537) on Monday April 07, 2008 @04:09AM (#22986528) Homepage
            (Patricia also prayed to God not to do anything miraculous during the course of the experiment, so as not to disqualify the findings.

            Oh man... I *so* want to be the one grading the projects and to sit down and talk with sweet little Patricia about her science experiment. I would be abundantly enthusiastic and impressed with all of her scientific work as I went over the various aspects of her project. I would be particularly impressed and particularly commend her on her thoroughness in considering that God could potentially interfere with the experiment and specifically praying to God not to do so...

            then I would get a thoughtful look on my face, and say "hmmmmmmm......"

            Hmmmmm, Patricia, your excellent work just made me think of something. I'm impressed by how you scientifically accounted for possible supernatural influence in the experiment, but are you certain you accounted for all such possible effects? You accounted for God, but is God the only potential influence? What about Satan? Did you scientifically account for Satan? What if a charcoal briquet, purified water, and a multi-vitamin *do* spontaneously create life when left in the sun, but what if Satan interfered and kept killing any such new life just because he wanted to invalidate your findings?

            You've done some excellent science work so far Patricia, and I don't want to score you badly for the oversight and inconsistent treatment of supernatural influences, so I'm going to let you take your project back so you can fix it. Do a new write up addressing the problem, and possibly re-do the experiment if necessary, and then bring it back to me when the problem is solved.

            Okay, I'm a cruel bastard with a twisted sense of humor. Chuckle.

            -
          • by tinkerton (199273)
            Looks like that site is made by the same people who run The Onion. One never can tell.
        • Re: (Score:3, Informative)

          by Peaker (72084)

          Anything that can be created by evolution

          Evolution is not the origin of life, it is the origin of species.

          The origin of life is thought to be some event whereby a self-copying structure was formed. Many believe this event is extremely rare. Perhaps it happens so rarely, that on one out of trillions of planets, in one of trillions of seconds, it happened by chance.

          It is possible that this event cannot reasonably be catalyzed in a non-intrusive way. For example, maybe you can increase the odds by a factor of many millions, by putting forth the co

          • by pkphilip (6861)

            If you try to catalyze it by causing the chemical reaction then the experiment may lose credibility.
            As a first step, we need to at least create this self-copying structure. We haven't even come close to doing this.

            The question of whether such a structure can come about without someone deliberately creating it is something that can be dealt with after we have created the self-replicating structure.
        • Re: (Score:3, Insightful)

          by timmarhy (659436)
          as usual, an epic fail in the understanding of science and evolution.

          evolution is what happened AFTER self replicating molecules happened. a rock doesn't just turn into a tin can as some massive retards try put forth, trillions of chemical reactions per second would have to happen for a billion years before you MIGHT run across a combination which has the ability to recreate itself.

          the difference between the scientists trying to explain this and religous people doing the same, is the scientists openly adm

      • by houghi (78078)
        Theologians can pursuade themselves of anything. Anyone who can worship a trinity and insists that his religion is a monotheism can believe anything -- just give him time to rationalize it.
        Robert A. Heinlein, JOB: A Comedy of Justice
    • Why is the creationism debate on Slashdot always posed as "Idiots who think God magiced the Earth into existence last tuesday*" vs "Reasonable people"? Outside the American South there are plenty of Christians whose belief as to the origins of life is compatible with the current science. I'm Christian and I believe Evolution is perfectly compatible, as do most other mainstream denominations. If God controls a complex system like the weather, then why would He have a problem with bringing about life through
      • Why is the creationism debate on Slashdot always posed as "Idiots who think God magiced the Earth into existence last tuesday*" vs "Reasonable people"?
        Can you describe it better in fewer words?
      • by jc42 (318812)
        Why is the creationism debate on Slashdot always posed as "Idiots who think God magiced the Earth into existence last tuesday*" vs "Reasonable people"?

        Heresy!

        It was last Thursday. Everyone knows that. Everyone who went to Thursday School as a child, that is. The rest are godless heathens, of course.

    • by Jugalator (259273)

      They may not understand how science works, but when faced with an article like this, can you really blame them?

      Everything looks hard when we don't understand it completely and it's barely out the doors of the universities.

      We teach basic theories on atomic nuclei where I live to 15 year olds, and most don't have too big trouble comprehending it. We have all those text books with pretty drawings, all explained in a concise way with a reasonably easy to understand language. All this would have been unthinkable the day papers on the atomic nucleus were starting to be published.

      I'd say -- just give it time. While what y

    • by nguy (1207026)
      1) A supreme being did it, or 2) blah blah amino acids blah blah meteorites blah blah neutron star light rays blah blah?

      The "supreme being" also comes with plenty of incomprehensible, meaningless jibberish: the Bible, the Koran, the Torah, etc.
    • by Doug Neal (195160)

      So y'know, take it easy on the creationists. They may not understand how science works, but when faced with an article like this, can you really blame them?

      We live in an age where we have more understanding of the world around us than we ever have before, and all this knowledge is freely available to anyone and everyone. There's no excuse for creationism and the fact that to this day it's still so popular is frankly an embarassment, and shows that modern science education is a dismal failure. If anything we need to go less easy on them.

  • Space sperm (Score:5, Funny)

    by Nimey (114278) on Sunday April 06, 2008 @10:47PM (#22985132) Homepage Journal
    Makes sense in a way: the meteors are sperm, the Earth the egg, the orbital bombardment the BDSM.
  • by teebob21 (947095) on Sunday April 06, 2008 @10:48PM (#22985140) Journal
    Interesting read. It has been one of the more pressing questions of the theory of biogenesis: where did the first organic matter come from? I have always found chirality and the left-handed nature of Earth's proteins to be more than mere coincidence.

    It is strange that our location in the galaxy led to a slight imbalance in the amount of gravitationally polarized light striking chunks of rock and metal floating in a cosmic dance 4 billion years before I was born....yet that combination of factors resulted in the alanine in my body to contain only the left-handed chiral.

    Studies like this are the cause of my personal religious dilemma. Most of the major religions came about 1500-5000 years ago...and at the time they were conceived, they convincingly explained every natural occurrence well enough to placate the masses. I wonder what the Pope would have to say about this study...was God a southpaw??
    • On a chemical level, life is mostly a whole mass of chemical chain reactions that form closed loops of events that (directly or indirectly) spread into multiple copies like glider-replicators in a game of life. A right-handed compound and a left-handed compound won't interact the same way ... so as the chain reaction "replicates", only one form gets passed on. That there would be a chirality bias is not surprising. On the contrary, I would say that it is the expected situation.
    • This is only "evidence," of course, and evidence can be brought on both sides of any case.

      On the other hand (perhaps I should read the article, correct me if I'm wrong), it does not appear to mention the huge step between having amino acid chains laying around and having them actually form a living cell organism. There's a huge difference between a pile of blocks and an actual functioning structure. Which is why, in old times, if your city got conquered, they "leveled" it. They knocked everything over.

      • by teebob21 (947095)
        Agreed - delivery of aminos is not delivery of life. I was going to make that point, but I gave the Slashdot crowd the benefit of the doubt that they would see it that way too. +1 to you, good sir.
    • Most of the major religions came about 1500-5000 years ago.

      Coincidently, written records go back to ~5000-6000 years ago, and the world is a red state.

    • Our amino acids are left handed because one of the ship's cooks who dumped their waste on our planet gave it a left-handed stir.

      However, "where did the first organic matter come from" is a no brainer. There are what, 6 * 10^23 carbon atoms in a mole (roughly 16g) of methane, the simplest organic, so imagine the number in the atmosphere of the early Earth because I can't be bothered to extrapolate to billions of tonnes. We already know that graphite spontaneously occurs in nanotubes, buckyballs and now graph

    • It is strange that our location in the galaxy led to a slight imbalance in the amount of gravitationally polarized light striking chunks of rock and metal floating in a cosmic dance 4 billion years before I was born...

      That's great for you, but what about the rest of us?!
    • Studies like this are the cause of my personal religious dilemma. Most of the major religions came about 1500-5000 years ago...and at the time they were conceived, they convincingly explained every natural occurrence well enough to placate the masses. I wonder what the Pope would have to say about this study...was God a southpaw??

      I've yet to find a religion worth believing in. I was raised up a Lutheran and was impressed with the pomp but looking at it as an adult, it's like going back to Disneyland and going on the Peter Pan ride. What was once magical as a kid become tacky with the "magic" now shopworn and obvious. You study these religions, you'll see all the seams where they were cobbled together, you see the crap and compromise. It's like learning your parents are human, just like you. Some see this loss of innocence as a sham

  • The fact that meterorite showers brought life to our planet is no mystery to me. See, I lived in Smallville for a while and I've seen things you wouldn't believe.

    - Chloe Sullivan
  • "Money shot" joke goes here.
  • "All earthbound meteors catch an excess of one of the two polarized rays." [which are generated by neutron stars]

    Doesn't this imply that there is a neutron star somewhere in the immediate vicinity of Earth that's zapping all our incoming meteors? Wouldn't we, um, notice?

    I mean, neutron stars are pretty rare things (~2000 known in our galaxy, nearest known is 280 lt/yrs away). I find it improbable that a significant majority of the incoming material has passed by one at some point in its life.
    • Presumably this happened around the time the Earth formed, or at least before life developed here. The neutron star has presumably long since drifted away.

      This sounds like it is another candidate solution to Fermi's paradox. If the genesis of life requires chiral chemicals (as suggested in the article), and if this only feasible through polarized neutron star radiation, and if such radiation events are rare then this could vastly reduce the number of planets in our galaxy expected to develop life. A lot
    • That's the problem with these theories

      Life started on a Meteor that has passed through special conditions not found in our solar system now or at any time, unlike the vast majority of rocks in our solar system which began here, crashes through the atmosphere, some of that life survives find favourable conditions and starts life....

      or

          Life started on Earth ....

      Occam's razor says the latter ...
  • How did life start is the key question, not where. The earth is an ideal place, lots of water and a long-lived sun. Why left-handed, maybe the just one first "living thing", molecule, whatever started it all. In a similar vein, why matter not anti-matter universe I believe is still up in the air.
  • by mbstone (457308) on Sunday April 06, 2008 @11:10PM (#22985266)
    Now that we know that life as we know it sprang from meteorite-sperm, we owe it to the rest of the Universe to immediately deploy Dyson condoms.
  • by MrKevvy (85565) on Sunday April 06, 2008 @11:12PM (#22985286)
    Someone correct me if I'm wrong, but I was under the impression that the left-handed chirality bias had already been explained by the non-conservation of parity in the electroweak force. The L enantiomers have a slightly lower binding energy, so in any mole of racemic amino acids you'll have about a million excess on the L side, which is enough to tip the balance.
    • by tinkerton (199273)
      I don't keep up and I can't access the references but this theory has been around for a while. Has it really been established that this factor will indeed tip the balance?
    • I don't see how it rules out the article theory. When reading the headline, I was thinking "WTF, how can radiation selectively chose one of two identical molecules", but if they are not exactly as stable, then maybe the radiations had destroyed a larger proportion of the less stable one and drastically tipped the balance.
  • OK, gotta bare my soul on this one (and luckily that's all I'm baring...).

    The thought that some meteorite from a distant star seeded life on earth just kicks me. A few days ago the Discover channel aired a documentary about black holes and supernovas. At some point it mentioned that our Sun too would eventually go boom and swallow the earth as some guy sips a drink at a Restaurant at the End of.. no never mind... OK, maybe it will go dark and the earth freezes over. Robert Frost is somewhere chuckling I'd g
  • by nguy (1207026) on Monday April 07, 2008 @04:26AM (#22986568)
    I'm not sure left handedness needs such a far fetched explanation. It makes sense for cells to pick one handedness or another, otherwise they need twice the machinery. And there are plenty of pathways that connect different amino acids and other compounds, so if one of them is left handed, chances are most of the rest are as well. And which handedness it ended up being may just have been chance.
  • I have long been a fan of the ideas presented in the book Genetic Takeover [amazon.com], but it always seems the science media is all about meteorites and Mars; I'm not sure if this is a product of the book being dated or the science media being no better than the regular media.

  • So I'll guess at the scientific origin of life: take the two most organic, chemically active elements and collide them. A meteor hit into the ocean and landed against an undersea volcanic vent. Even if we have no evidence that this is how life formed, just imagine all the chemical reactions and elements that came together when this (statistically likely) happened (at some point in the past).

In the sciences, we are now uniquely priviledged to sit side by side with the giants on whose shoulders we stand. -- Gerald Holton

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