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Earth Space Science

Life's Building Blocks Found On Asteroid 24 Themis 135

Posted by timothy from the pinning-down-origins dept.
Hugh Pickens writes "The LA Times reports that scientists analyzing infrared light reflected by 24 Themis, one of the largest asteroids in the solar system, have discovered evidence of water ice as well as organic compounds — findings that bolster a leading theory for the origins of life on Earth that the essential building blocks of life came from asteroids. 'Up until now there was no sign that asteroids had any abundant organics or ice on them,' says Joshua P. Emery, a planetary astronomer at the University of Tennessee. Typically, ice on the surface of an object such as 24 Themis would quickly vaporize and vanish, says planetary scientist Richard Binzel. 'Seeing freshly exposed ice on the surface, now that's a surprise. It has to be replenished from below, somehow.' The possibility that water could have come from asteroids adds weight to the theory that water and organic molecules may not have originated on Earth because the Earth did not become conducive to water or organic molecules until relatively recently."
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Life's Building Blocks Found On Asteroid 24 Themis More

Life's Building Blocks Found On Asteroid 24 Themis

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  • A Few Skeptical Points (Score:5, Interesting)

    by CheshireCatCO ( 185193 ) on Friday April 30, 2010 @07:22AM (#32042866) Homepage

    If their argument is that early Earth wasn't conducive to water, it's not clear how bringing in organics and water would help. If you bring in organics to a hot planet, they'll break apart just as surely as if they had formed there, after all.

    It's never been clear to me why this mechanism is any better than just forming the danged organics on Earth surface. The Urey-Miller experiments demonstrated nicely that you can form organics under a wide range of conditions. (Which ones correspond to early Earth is an outstanding question, but it doesn't appear to much matter, oddly.)

    Come to all that, we don't know that these asteroids (assuming they are asteroids and not dead comets, which it kind of sounds like they may be...) had much in the way of organics 4 billion years ago or if the organics formed due to reactions since then.

    Basically, I'm uncomfortable with how excited people seem to get about the idea that this might have delivered the "building blocks of life" to Earth. Possible, sure, but it's far from a strong case.

    • Re: (Score:2, Interesting)

      by Loomismeister ( 1589505 )

      Actually it's almost inevitable that organic compounds made it to earth via asteroids at some point. Organic compounds are really common on other planets and moons even in our solar system.

      Whether or not the asteroids started the evolution of life on earth is hard to tell, but does it really matter? This is just one more way to explain why earth billions of years of ago sparked life.

      Their theory is plausible at the least.

      • Re:A Few Skeptical Points (Score:4, Insightful)

        by CheshireCatCO ( 185193 ) on Friday April 30, 2010 @07:43AM (#32042980) Homepage

        Whether or not the asteroids started the evolution of life on earth is hard to tell, but does it really matter?

        First of all, "evolution" isn't the issue here, it's biogenesis. Different concepts and it's important to keep them straight. (If only to keep the Creationists from confusing the two more than they already do.)

        Second, yes, it matters. If the argument is, "Hey, meteorites have delivered organics, but Earth already had plenty," fine, but
        a) That's not what people, especially researchers, keep saying.
        b) No one cares if there's no connection to the terrestrial biogenesis. (OK, not no one. It's an interesting datum, but it lacks the cache to get published in the popular press.)

        • Usually it's called "Abiogenesis", life from non-life. And it would be the start of evolution as parent had said.

          Different concepts and it's important to keep them straight.

          But yes, agreed.

          Now, I'm not a cosmologist or anything, but I think Mr. Scientists isn't mentioning that "earth already had plenty" because the Earth did not become conducive to water or organic molecules until relatively recently.

          And I care about this news because it lends weight to the idea that life can be more abundant in the universe. Which would be awesome. This might be the best news

          • "abiogenesis" means start of life from non-life. I dropped the prefix because I don't care where the life comes from in this case. (If meteorites bring in living organisms which colonize Earth, that's biogenesis for Earth, but not abiotic.)

            Now, I'm not a cosmologist or anything, but I think Mr. Scientists isn't mentioning that "earth already had plenty" because the Earth did not become conducive to water or organic molecules until relatively recently.

            And that's what I'm taking issue with. If the planet couldn't support water and organics, it couldn't support water and organics. Space-organics are just as fragile to heat as terrestrial-made versions.

            Also, "relatively recently" is pretty lame in this case. The firs

            • Well I don't think that anyone is calling these compounds alive. (Except that crazy fucker calling them dinosaur bones). They just have carbon in them. So if this stuff fell to earth and life sprouted from it, it'd still be considered abiogenesis. And if life originated elsewhere and then came to earth, those lifeforms had to start somewhere so abiogenesis is still involved.

              As for the other points, yeah, ok.

              • In this case, yes, no one is calling them "alive". But the panspermia hypothesis does speculate that live could be delivered here, so I didn't want to rule that option out is all. :-)

            • Re: (Score:3, Interesting)

              by geekoid ( 135745 )

              "Space-organics are just as fragile to heat as terrestrial-made versions."

              that's actually unknown. They could be more adaptable to space, but the properties for that environment where no longer required after being on earth. So they weren't need to evolve.

              I don't care where it started, but if w did get her vie space seeds, then not only does it increase the likelihood of life elsewhere.

              If ti turns out the the properties of space organics is as fragile as you speculated, that means other life out there may b

              • No, it's known that they're just as fragile. Making a molecule in space yields the same physical chemistry as making it on Earth. The dissociation energy is the same (unless you're arguing isotopic fractionation, which shouldn't change things much either way).

            • Also, "relatively recently" is pretty lame in this case. The first 10% of Earth's history was inhospitable for life. We know it quickly recovered because there's evidence for life going back between 3.8 and 4 billion years.

              Actually, we have good reason to believe that the Earth's surface has been not-incompatible with life for 4.2 or possibly even 4.3 billion years ; that's around 95% of it's history so far. Or from the other end of the telescope (stopwatch), it halves the amount of time between the formati

              • I was actually thinking of the oxygen ratios in the Greenland rocks, which go back 3.8-4 bya, but I was aware of the Australian zircons as well. I hadn't heard/didn't recall them showing the fractionation beyond 4 bya, though. I find it difficult to imagine Earth being very conducive to life before this with the Late Heavy Bombardment ending around this time.

                • There was a paper on this a few months ago. (Again, I'm typing on my lap at an awkward angle, so I'll make this short) Gist of the work is that once significant water was around (brought in by the LHB??), then the deeper parts of the ocean would be significantly buffered from the scalding pummelling that the surface was getting. With major impacts coming on only every few thousands of years ... something that could survive hot water in the deepest parts of the oceans would have a reasonable chance of surviv

                  • Even before you got the last bit, I was thinking, "That would explain why the tree of life is rooted in the thermophiles." Nice. :-)

        • Re: (Score:2)

          by Urkki ( 668283 )

          Second, yes, it matters. If the argument is, "Hey, meteorites have delivered organics, but Earth already had plenty," fine, but
          a) That's not what people, especially researchers, keep saying.
          b) No one cares if there's no connection to the terrestrial biogenesis. (OK, not no one. It's an interesting datum, but it lacks the cache to get published in the popular press.)

          The interesting/important bit is, could all the necessary step, all the necessary chemical reactions, have happened on pre-biotic Earth fast enough or at all. Different phases needed in the development of self-replicating organic systems (ie. "life") require different environment (chemicals present, pH, temperature, radiation, all that...).

          I'd say it's more than likely that some essential molecules formed in space and then landed on Earth, because there were no suitable environment on Earth for them to form

    • I am not an astronomer but there also seems to be a lot of improbable things in this story. Obviously it's odd to find ice and organics on an asteroid but not impossible. But it's the first asteroid (24 Themis) these two teams have independently looked at. It's evenly distributed on the surface as well which is also odd. And it has to be replenished from within -- which I think challenges a lot of assumptions about asteroids -- otherwise this water would have baked away a long time ago. These last two

      • Re:A Few More Skeptical Points (Score:5, Interesting)

        by mrsquid0 ( 1335303 ) on Friday April 30, 2010 @07:44AM (#32042988) Homepage

        The water on the surface of 24 Themis does not have to come from within the asteroid, it can be created through surface chemistry between the solar wind and the surface of the asteroid. The process is similar what has been proposed to explain some of the water layer found on the surface of the Moon. In essence, the water on the asteroid is being continually created. Water that is lost is replaced through chemical reactions over time.

      • I'm not sure how the Yarkovsky effect, which alters orbits, would redistribute water.

        As for spectroscopy, it's a fairly well-established and reliable method. Probably more than half of astronomy relies on it, in fact. So I'm willing to trust them when they say there are organics up there.

      • Re: (Score:3, Insightful)

        by TapeCutter ( 624760 ) *
        "I'm glad that two teams independently verified it but I'm a little concerned that there may be a flaw in the methodology of the reflection of the light. I'm sure they've accounted for everything but I'm just concerned because the only logical explanation is either our fundamental understandings of asteroids is largely incomplete (the first one they picked was laden with organic molecules where normally there are but a few traces) or the methodology of determining their composition falls prey to some unfore

    • Re: (Score:2, Interesting)

      by Em Emalb ( 452530 )

      The thing I don't get is how "finding signs of water" and the "basic building blocks of life" on asteroids/other planetary elements is such a huge deal. Logic indicates with hundreds of billions of planets in the universe that water or other "basic building blocks of life" would be present on at least some other elements in the universe.

      • Logic indicates with hundreds of billions of planets in the universe that water or other "basic building blocks of life" would be present on at least some other elements in the universe.

        Logic also indicates that a heavier object would fall faster than a lighter one. Except, of course, that both your claim and my counter-example are based on a series of presumptions for which there is not appropriate evidence. Empirical science requires a balance of evidence/data and logic, and, in the end, evidence trumps logic (hence - the falsification of theories).

    • Re: (Score:3, Insightful)

      by Yvanhoe ( 564877 )

      It's never been clear to me why this mechanism is any better than just forming the danged organics on Earth surface. The Urey-Miller experiments demonstrated nicely that you can form organics under a wide range of conditions.

      Yes, I too wonder why people bother to report discovery of simple carbon compound that we know can be easily synthesized in any soup with the good elements.

      I always thought the panspermia hypothesis supposed that some basic life forms could cross interplanetary (or even interstellar) gaps thanks to asteroids. It doesn't seem to be the most favored hypothesis for the apparition of life on earth but it could lead to interesting things if it was confirmed. However, the Urey-Miller experiment showed us that

    • Re: (Score:2)

      by kv9 ( 697238 )
      send Bruce Willis to investigate. or just blow it up.

    • The theory goes that a mars sized planetoid, named Theia, had formed at earths L4 or L5 Lagrangian points. As it's mass grew due to impacts, it was no longer stable at that point, and slammed into earth. The resulting debris cloud came together to form the moon.

      See http://en.wikipedia.org/wiki/Giant_impact_hypothesis

      • Yes, thank you. I'm aware of that, but I'm not sure why you mention it. It's not a question I was asking in the first place and it's not really the reason Earth was inhospitable for water and organics. (Also, I'm fairly skeptical of the Lagrange point model. I have never seen any reason that you'd need it to form there or that it would even be likely to do so. It strikes me as a horrible place to form a second planet.)

        Earth was inhospitable for a variety of reasons, including the frequent bombardment o

    • Re: (Score:2)

      by rcamans ( 252182 )

      Where did the asteroids get their organics? Are they saying that they formed on the asteroids? Then how would that stuff ride the asteroid to earth? Doesn't the whole asteroid burn up on reentry? Or if it doesn't, doesn't the impact sterilize the impact site? Leaving an insignificant amount of organic chemicals to supposedly cause life?
      These so-called scientists are going way out on a limb. Someone explain to them Occam's Razor.

      • Organics can be delivered to Earth on meteorites. The interiors don't get hot. ALH84001 seems to show exactly this. (You can debate the possibility of contamination from the Antarctic, but it's not overwhelmingly obvious that that's what happened.) The question is less, "Can we get organics?" and more, "Can we get the majority of the early organics that way?"

  • Not testable (Score:5, Informative)

    by TapeCutter ( 624760 ) * on Friday April 30, 2010 @07:33AM (#32042928) Journal
    "findings that bolster a leading theory for the origins of life on Earth that the essential building blocks of life came from asteroids."

    No it doesn't, that "leading theory"(*) is untestable and completely ignores contra evidence. Hydrogen, Oxygen and Carbon are respectively the 1st, 3rd and 4th most abundant elements in the universe. Hydrogen and oxygen combust to create water. Modern day volcanos spew all three elements out in large quantities, mainly as water vapour and carbon based molecules. If a rock 100 odd km across has organics and water what in the world make anyone think that a rock over 6000 km in diameter formed from the same primordial material would have have none?

    While it's certainly very likely that some water and organics arived via asteroids, frankly the ridiculous improbability that ALL of it arrived via asteroids is too fucking stupid for words. Such psuedo-scientific claptrap only detracts from what is an otherwise fascinating discovery.

    (*) = Here is what a real leading theory for abiogenisis [youtube.com] looks like; "no ridiculous improbability, no supernatural forces, no lightning striking a puddle, just chemistry", and with a great soundtrack to boot!

    • Re: (Score:3, Insightful)

      by danbert8 ( 1024253 )

      I was confused by this article for a similar reason. Isn't the earth just a big ol' ball of rock formed by the collisions of a bunch of asteroids that were orbiting in a cloud while the sun was forming? No shit the stuff on earth came from asteroids, the earth was FORMED by asteroids. One way or another, everything on earth has extraterrestrial origins because it had to come from somewhere, and the earth hasn't always existed.

      • "...the earth was FORMED by asteroids. One way or another, everything on earth has extraterrestrial origins..."

        Exactly, and the more we look the more we are finding that water and simple organics are ubiquitous components of the universe.

      • Re: (Score:2)

        by Tim C ( 15259 )

        Isn't the earth just a big ol' ball of rock formed by the collisions of a bunch of asteroids that were orbiting in a cloud while the sun was forming?

        That and the collapse of the Sun's accretion disk under self-gravity, yes.

    • Re: (Score:3, Interesting)

      by Stenchwarrior ( 1335051 )

      Very impressive video and I tend to agree: It seems probable to me that the basic life-giving elements could have been delivered via abiogenisis AND space, since it's all basically made up of the same stuff. Just like the early organisms being bounced around in the oceans and picking up new parts, why couldn't the universe be considered just one huge ocean where all the rocks (whether planets or asteroids) have the same parts and the big ones borrow from the small ones?

      Very cool

      • Re: (Score:2, Insightful)

        by TapeCutter ( 624760 ) *
        "Just like the early organisms being bounced around in the oceans and picking up new parts, why couldn't the universe be considered just one huge ocean where all the rocks (whether planets or asteroids) have the same parts and the big ones borrow from the small ones?"

        This is an example of why I've persisted with slashdot for a decade. That's a very interesting analogy!

    • Re: (Score:2)

      by Zumbs ( 1241138 )
      Indeed. Whenever I hear the theory that the building blocks of life came from asteroids, I can't help being reminded of another "popular" theory: That the pyramids were built by aliens, and not by the Egyptians (or, possibly, their slaves). I'll check out the video when I get the time.
    • Interesting to think that with the information on that video, there is an extremely good chance of life on Saturn's Enceladus, at least in the form of these simple vesicles. Enceladus has the water, carbon, nitrogen, and heat that is all that's needed to make these vesicles form spontaneously.

      Whether they have evolved into anything more complex depends on the stability under the ice (do these vesicles continuously get eradicated or have they been given time to "compete" with one another).
      • Yes, we have only just begun to explore our solar system. Personally my favorite target for complex multi-cellular life is the sub-surface oceans of Europa but there is certainly no shortage of interesting targets for simple single celled life forms in our solar system and Enceladus is high on that list as are the seasonal methane plumes of Mars.

    • (*) = Here is what a real leading theory for abiogenisis [youtube.com] looks like; "no ridiculous improbability, no supernatural forces, no lightning striking a puddle, just chemistry", and with a great soundtrack to boot!

      Pantera (with a lot of help from Sabbath) did one two:
      http://www.youtube.com/watch?v=Gym2UXYRz98 [youtube.com]

      (note that this damned Pulse Audio is broken and I can't listen to it!)

    • Re: (Score:2)

      by lwsimon ( 724555 )
      TY for the video link - nothing really new to me, but it was interesting to see it put together in one place.

    • Re: (Score:2)

      by geekoid ( 135745 )

      " that "leading theory"(*) is untestable"

      Only do to engineering reason. One can easily design a test to try and falsify the theory. Implementation is difficult at this time.

      "contra evidence"
      that is nonsense. It's observable data. One that happens to lead to a different theory. More data will refine, change, or remove they theory.

      " over 6000 km in diameter formed from the same primordial material would have have none? "
      no one. Why do you think they are?

      "no ridiculous improbability"
      no more probably then pansp

      • "that is nonsense. It's observable data. One that happens to lead to a different theory. More data will refine, change, or remove they theory."

        I think your definition of the term "contra evidence" does not align with the accepted one, contra eveidence is evidence used to falsify the theory in question. The facts that I mentioned falsify the theory that ALL water and organics arrived by asteroid.

        "You know, they BOTH could very well be true."

        Yes, this was my point, they both ARE true. There is no di

  • not leading, wacky! (Score:2, Informative)

    by metageek ( 466836 )

    "findings that bolster a leading theory for the origins of life on Earth that the essential building blocks of life came from asteroids"

    bullshit, this is not a leading theory, rather calling it a "wacky theory" could be a better description...

  • Free propellant! (Score:5, Interesting)

    by justthisdude ( 779510 ) on Friday April 30, 2010 @07:50AM (#32043026)
    Life, Shmife! We are not focusing on the most important aspect of this report. The key is that there is sizable amounts water available in (relatively) nearby orbits outside of any significant gravity well. If the water can be used to refuel ships on their way to outer orbits, this could be incredibly useful for deep space exploration. I would personally prefer to see a space station on 24 Themis than on the moon, and it is less work to get there. Ok, more time but less work.

    • Life, Shmife! We are not focusing on the most important aspect of this report. The key is that there is sizable amounts water available in (relatively) nearby orbits outside of any significant gravity well.

      You really don't consider the Sun to have a significant gravity well?

    • Re: (Score:2)

      by geekoid ( 135745 )

      really, the probability of life going up in the universe isn't the big story? seriously?

    • Re: (Score:2)

      by elrous0 ( 869638 ) *
      Asteroids, smashteroids! The most important aspect of your post is the revelation that water can be easily used as fuel. Forget asteroids, let's convert some of these useless oceans here to power my car and house.

      • Asteroids, smashteroids! The most important aspect of your post is the revelation that water can be easily used as fuel. Forget asteroids, let's convert some of these useless oceans here to power my car and house.

        Duh. Steam powered rocket.

  • It would be interesting if life in the Universe was similar enough because planets that bear life are "seeded" in such a way. Frightening, too. That means it's possible that humans might be susceptible to microbes found on other planets.
    • Don't fear things you don't know about, it's a hard way to go through life. That goes double for things that exist only in theory.

    • Re: (Score:3, Insightful)

      by Valdrax ( 32670 )

      It would be interesting if life in the Universe was similar enough because planets that bear life are "seeded" in such a way. Frightening, too. That means it's possible that humans might be susceptible to microbes found on other planets.

      That statement belies an amazing ignorance about how tightly adapted diseases are to their hosts. You do realize that we're immune to all but the tiny fraction of microbes on Earth which are adapted to live in the ecosystem that is our bodies, right? Why would random space microbes be capable of surviving inside of us?

      We can't even get most of the same diseases dogs get, much less germs that survive on frozen, irradiated asteroids.

      • We can't even get most of the same diseases dogs get, much less germs that survive on frozen, irradiated asteroids.

        Yeah, most. Just keep that in mind when you're on Arcturus. Lots of people have learned a painful lesson from telling themselves there's no way Space Clap is compatible with human hosts.

  • So where then did these Asteroids get the water and organic compounds? Is there a universal pick-up point or 'building blocks for life' fly-thru in a far distant corner of somewhere?

    • Re: (Score:2)

      by Valdrax ( 32670 )

      The non-crazy part of panspermia theory that makes it semi-attractive to some folks is that the available area for the formation of these building blocks within the solar system is much greater than on just the surface of the Earth. (Consider the asteroid belt, various trojan asteroids, the Kuiper belt, comets, and the theorized Oort cloud.)

      The crazy part is the notion that this means the probability of forming off planet is inherently greater and that many of these building blocks would be more likely to

    • Re: (Score:2)

      by PPH ( 736903 )
      The water and organic compounds are all that remain of the planet and advanced civilization that existed on the planet in that orbital position before Marvin the Martian blew it up with an Illudium Q-36 Explosive Space Modulator. It was blocking his view of Jupiter.

  • It's a disguised alien spacecraft.

  • Life's Building Blocks Found On Asteroid 24 Tennis

    Never read Slashdot until you're fully awake.

    • I also read that wrong:

      Life's Building Blocks Found On Asteroid 24 Times

      I opened TFA just to figure out what was wrong with the first 23.

  • Whether this "implies" that the building blocks of life were delivered via this method is a secondary hypothesis. I feel that a more important implication is that these "building blocks" can develop in a particularly harsh, non-earth environment. This gives more credence to the notion that life could have arisen on the primordial earth as postulated by science. And it gives credence to the notion that life may well have arisen elsewhere in the universe.

  • Of course, in that case, it's not so much terraforming as 'somewhereelse-forming'.

    And they'll be along soon to clear off the rodents from the planet they prepared earlier...

  • It's not a theory. It's a hypothesis. IIRC, a theory is osmething that has already been tested, correct? Hypotheses haven't. Obviously, this hypothesis has not been tested much, or "woohoo, we found it on an asteroid!!" wouldn't be news, it'd be old news ... something that had already been done.

    I really don't think that a "hey, I think they came from asteroids" idea becomes a theory before you actually prove that the stuff even exists ON an asteroid?

  • Let's send captain Cirocco Jones and the crew of the DSV Ringmaster to check it out!

  • I shouldn't have put my tongue to the ice last time I was there. I must have left some of it behind

  • The asteroid is the seed, we are the crop.

    The harvesters are coming.

  • I suppose the theory is that once it boils, it's gone, but that's terribly naive. Once it boils, it's in the atmosphere, where it will happily stay until the planet cools enough for it to condense.

    Why are we looking for reasons why abundant elements form common molecules? We don't need water FROM anywhere. Everything needed (hydrogen, oxygen) would have been part of the dust and gas cloud that condensed to form the earth.

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