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Comments: 116 +-   Scientists Look at Martian Salt for Ancient Life on Monday March 31 2008, @02:37PM

Posted by ScuttleMonkey on Monday March 31 2008, @02:37PM
from the would-you-like-fries-with-that dept.
space
science
eldavojohn writes "Is there life on Mars? Maybe not, but a better question might be whether or not it has ever existed on Mars? Scientists are claiming that the best indication for this will be in newly found evaporated salt deposits on Mars which they can use to check for cellulose. Here on earth, tiny fuzzy fibers have been found in salt dating back almost 250 million years making it the oldest known evidence of life on earth. Jack Griffith, a microbiologist from UNC, is quoted as saying, 'Cellulose was one of the earliest polymers organisms made during their evolution, so it pops out as the most likely thing you'd find on Mars, if you found anything at all. Looking for it in salt deposits is probably a very good way to go.'"
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Submission: Scientists Look at Martian Salt for Ancient Life by eldavojohn (898314)
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  • Salt and astrobiology (Score:5, Informative)

    by Geoffrey.landis (926948) on Monday March 31 2008, @02:40PM (#22924146) Homepage
    Salt on Mars has been a topic of interest for a while-- I wrote about the implications of Martian salt for Astrobiology a couple of years back, in an article in Astrobiology [liebertonline.com]
    • I wrote about the implications of Martian salt for Astrobiology a couple of years back, in an article in Astrobiology

      Wait, wait, was your article about the implications of Martian salt for the science of astrobiology? Or the implications of Martian salt for the publication Astrobiology?

      Inquiring minds want to know!
  • D.E.L.I.C.I.O.U.S. !

  • slightly inaccurate summary (Score:5, Interesting)

    by cowscows (103644) on Monday March 31 2008, @02:47PM (#22924220) Journal
    The article summary says that the cellulose found in 250 million year old salt is the oldest known evidence for life on Earth. That's not true, there's ample of evidence of life for billions of years before that. The article states that the 250 million year old salt is the oldest biological substance known, which is pretty cool, but there are plenty of other types of evidence for life besides just finding dead tissue.
      • Feel free to swing by any college library you like. They have an entire section.

        • Re: (Score:2, Funny)

          by Anonymous Coward
          He can't do that. He's too busy at church.

      • Re: (Score:3, Insightful)

        by Gat0r30y (957941)
        Radioactive decay is a pretty well understood phenomenon. The strong force (and weak too) in the nucleus of radioactive elements isn't quite strong enough to contain all the protons and neutrons in there, causing alpha and beta particles to come flying out from time to time (causing decay to another element in the case of a proton, and another isotope in the case of a neutron). By measuring the ratio of isotopes, we can figure out when a rock was formed. And, it all fits quite neatly in our standard mode

          • Re: (Score:3, Insightful)

            by Chris Burke (6130)
            Well, the way it works for organic tissue and radio-carbon dating is that new higher isotopes of carbon are being created all the time, and have a generally equal distribution in the environment at large. When an organism is alive, it will continuously take in new carbon from the environment (food, CO2 for plants, etc) and thus maintain the same ratio of carbon isotopes. When it dies, however, it stops taking in new carbon, and thus slowly the existing radioactive isotopes will decay and not be replaced s

          • Re: (Score:3, Interesting)

            by MightyMartian (840721)
            Start here. It also includes all the necessary references for going to the primary literature if you think all those evil atheist scum in talkorigins.org are just making it up:

            http://talkorigins.org/faqs/faq-age-of-earth.html [talkorigins.org]

            In fact, I suggest you probably spend some time at that site.

      • http://en.wikipedia.org/wiki/Stromatolite (Score:4, Informative)

        by sofar (317980) on Monday March 31 2008, @03:27PM (#22924564) Homepage
        http://en.wikipedia.org/wiki/Stromatolite [wikipedia.org]

        Quote:

        "The earliest stromatolite of confirmed microbial origin dates to 2,724 million years ago."

  • Return Sample? (Score:5, Informative)

    by Gat0r30y (957941) on Monday March 31 2008, @02:48PM (#22924224) Homepage Journal
    Wouldn't this require a sample coming back here? It looks like they needed a Scanning Electron Microscope to see the cellulose fibers. It seems to me they would have to return a sample of the salts in order to see anything. Are there any plans for a sample return mission to mars anytime soon?
    • they needed a Scanning Electron Microscope....Are there any plans for a sample return mission to mars anytime soon?

      I hope not. The possibility that it may contaminate Earth with a Mars infection we have no immunity for is too high. Even a 1-in-a-million chance is not worth it. Would you want to take a 1-to-million gamble with all of humanity? (Please, no G.W.Bush jokes). We'd probably need to set up an orbiting or moon base lab for that so that any infected workers are incubated away from Earth for at lea
      • You've been watching too much sci-fi...It's unlikely that something from such a wildly different evolutionary line would even be infectious to us. It's still pretty rare that diseases jump species here and everything on Earth is pretty closely related, genetically speaking.

        The odds of finding a living, viable, martian disease that likes people are about the same as finding a herd of giraffes roaming around up there.

        • Re:Return Sample? (Score:5, Insightful)

          by Tablizer (95088) on Monday March 31 2008, @03:26PM (#22924560) Homepage Journal
          You've been watching too much sci-fi...It's unlikely that something from such a wildly different evolutionary line would even be infectious to us.

          1. We don't know that with any certainty. It may end up being a "contest" to see which side can evolve an advantage over the other first before immunities are built up by both sides.

          2. Mars life may be related. Studies suggest asteroids can blast spores betweens planets.

          It's still pretty rare that diseases jump species here

          But species jumpers also tend to be some of the deadliest. Livestock are notorious for producing whoppers.
             

          • Re:Return Sample? (Score:4, Interesting)

            by SatanicPuppy (611928) * <<Satanicpuppy> <at> <gmail.com>> on Monday March 31 2008, @03:55PM (#22924826) Journal
            I don't honestly think there will be any evolutionary pressure, simply because there is no vehicle for it. In the case of livestock viruses, those viruses are passed around the animal populations for huge amounts of time before one manages to jump the divide. We live in close proximity to the livestock, so there is a good chance, given enough time, that a virus will mutate in just the right way, and that that mutation will happen in the right time and place to find a suitable host.

            None of that applies to a theoretical martian virus that's got no growth vector and no suitable host animal that it's evolved to live in, that we like to hang out with. It would have to have us nailed the first time, no tests, no practice. That's pretty damn unlikely.

            The asteroid thing is of course possible, but again pretty unlikely. In that scenario, it'd be more likely that we've already been infected with martian bacteria and have built up immunity than it is that our whole ecosystem is parallel to theirs, and their theoretical hostile bacteria are out there now, waiting.
              • The situations are not analogous. In the case of foreign invasive species, you are, in fact, dealing, relatively speaking, with closely related organisms. Rabbits can, by and large, eat the Australian plants, because only a few hundred million years of evolution separate the plants from an ancestor of the rabbit that could process the food.

                If there was a common ancestor between life on Earth and some hypothetical Martian life, that common ancestor would likely date back over three billion years ago, which
          • If there is life on Mars, and if it is related in any way to life here (those are two really big ifs), there is still billions of years of divergent evolution here. Other than the possibility that such life might belch out chemical compounds that might be poisonous to Earth life, I think the likelihood of something that could actually infect any modern organism is exceedingly unlikely. I'd wager that if there is life on Mars, it would likely find our oxygen-nitrogen atmosphere quite poisonous, and would p
              • You can never say anything with absolute certainty. I can't say with any certainty that the minute you turn away from your computer that a meteorite won't strike you right between the eyes. I can say it doesn't seem very likely. Biochemistry is a finicky thing and while one can't say that there might not be some risk, billions of years of specialized evolution means that both ecosystems would likely be quite incompatible.

        • You've been watching too much sci-fi...It's unlikely that something from such a wildly different evolutionary line would even be infectious to us. It's still pretty rare that diseases jump species here and everything on Earth is pretty closely related, genetically speaking.

          Don't bother with that-- if Martian organisms are halophilic, they could not survive in a salt concentration as low as that in our bloodstream, or our oceans; they would literally fall apart.

          ...and if they're not halophilic, they wouldn't survive on Mars.

      • I hope not. The possibility that it may contaminate Earth with a Mars infection we have no immunity for is too high. Even a 1-in-a-million chance is not worth it. Would you want to take a 1-to-million gamble with all of humanity?

        I agree with your sentiment about gambling with the lives of all of humankind, but is there any evidence to suggest that 1:1000000 are reasonable odds given:

        • Unlikelihood that there is present life on mars
        • Unlikelihood that it will survive the sample return mission
        • Unlikelihood

  • 250 million? (Score:3, Insightful)

    by Tablizer (95088) on Monday March 31 2008, @02:49PM (#22924230) Homepage Journal
    Here on earth, tiny fuzzy fibers have been found in salt dating back almost 250 million years making it the oldest known evidence of life on earth.

    Earth cellular life evidence dates back to about 4 billion years if I remember correctly. Even some trilobite fossils date to around 530 million years ago. Perhaps they meant "250 million years since the formation of Earth"? Its a trick to make me RTFA to find out what they really meant.

           

  • No, not oldest evidence of life (Score:4, Informative)

    by mck9 (713554) on Monday March 31 2008, @02:49PM (#22924232) Homepage
    No, these aren't the oldest known signs of life on earth. There are fossils way older than 250 million years. According to the article, this fuzz is the oldest known **biological material** on earth. Not the same thing.
  • I thought Stromatolites were the oldest known evidence of life on earth?
    • Actually, I believe that the oldest evidence for life is in the isotope ratios in rocks. It's indirect, but it also relies less on chance than fossilization. (Basically, biological processes tend to use more of one isotope than another, leaving the atmosphere enriched relative to the background. So this is a tracer for the presence of biological activity.)
      • Do you have a quote on that preferential absorption of isotopes? The reason isotope ratios can be used to date materials (like Carbon 14 for recent events) is not that biological processes incorporate C14 preferably, but that they incorporate it at all. So once the biological activity stops, so does the C-14 absorption.
        • I think the parent may be misremembering the Oxygen Catastrophe [wikipedia.org]. That began well over a billion years after the first life appeared on Earth. I believe we know about this due to deposits of iron oxide, which could only form in the presence of oxygen, and point to a period when all those wonderful early organisms had farted enough molecular oxygen into the atmosphere to start the process (and probably poison a lot of organisms in the process).

          I imagine it is possible that in certain reactions, certain isot
        • A quote, no. But I believe that Steve Mojzsis has published work on this, if that helps. He explained it to us in graduate astrobiology, but a) I'm an astrophysicist and b) it was almost a decade ago, so I won't swear to be able to quote stuff back to you.

          The gist of it, as I recall, is that heavier isotopes react more sluggishly than lighter ones.

  • Bad Summary (Score:5, Informative)

    by algae (2196) on Monday March 31 2008, @02:53PM (#22924258)

    Here on earth, tiny fuzzy fibers have been found in salt dating back almost 250 million years making it the oldest known evidence of life on earth.

    What the article actually *says*, is that the fibers themselves are 250 million years old, making them the oldest known biologically-produced material. There's obviously older evidence of life to be found on Earth.

    While I'm nitpicking, "Earth" is capitalized, as it is a proper name.

    • What the article actually *says*, is that the fibers themselves are 250 million years old, making them the oldest known biologically-produced material. There's obviously older evidence of life to be found on Earth.

      I don't think that's quite accurate either. Certainly banded iron formations predate all of this by a couple of billion years. I guess cellulose may be the oldest surviving organic materials, but the evidence of life leaving behind different materials is much older than that.

  • I wonder what the middle eastern religions, the trifecta judaism, christianity, and islam, will have to say about it. Either the universe is teaming with life, or we are the only ones. I find it hard to believe we are the only ones, so sooner or later will find proof of life somewhere.

    • I wonder what the middle eastern religions, the trifecta judaism, christianity, and islam, will have to say about it. Either the universe is teaming with life, or we are the only ones. I find it hard to believe we are the only ones, so sooner or later will find proof of life somewhere.
      Heh, I've always wondered the same thing. I'm sure the quick-thinking clergymen will find a way to incorporate this into their religion. Hell, the Bible's open for interpretation, right?
      • ...thus solving our problem once and for all.....ONCE AND FOR ALL!!
        • There has been evidence for evolution since Darwin, hell, since the pyramids were built. Religious conservatives are fairly famous for saying things like "I see your evidence. Show me different evidence, evidence that supports my opinions." Just ask Galileo [wikipedia.org].

    • I wonder what the middle eastern religions, the trifecta judaism, christianity, and islam, will have to say about it.

      Religion has survived much more "dangerous" things than finding evidence that there used to be bacteria on Mars. I would imagine they will say something along the lines of "It is the glory of God to conceal a thing: but the honour of kings is to search out a matter."

      Either the universe is teaming with life, or we are the only ones.

      Or it could be anywhere in between. We have no idea what

    • Re: (Score:2, Informative)

      by Bartab (233395)
      It will be a non-question unless/until other intelligent life is found. A life filled universe will not contradict any of those religions.

  • Slug! (Score:3, Funny)

    by Tablizer (95088) on Monday March 31 2008, @03:00PM (#22924322) Homepage Journal
    So my fantasy about pouring salt on a giant Mars Slug to save the astronaut colony still holds hope.
    • Good news is, with the discovery of salt on Mars, you don't have to pack your own all the way across millions of kilometers. That's a looooooooong way to go to find a 7-11, you know...

  • Why? (Score:3, Insightful)

    by rrohbeck (944847) on Monday March 31 2008, @04:13PM (#22925016)
    What's the probability that life on another planet evolved the same type of chemistry and the same type of macromolecules?
    If they found cellulose, I'd argue that it is from organisms that originated on earth. Now if they found (micro)fossils that are completely different from anything we know I'd listen up.

    • Re: (Score:3, Interesting)

      by MightyMartian (840721)
      I honestly don't know enough about complex chemistry to answer any question like that. I would suspect, however, that for any carbon-based life, carbohydrates are going to be an absolute requirement for releasing and utilizing energy (ie. ATP). In that case, you're likely going to find related chemistry (starches, cellulose, etc.) in such ecosystems, even if they are unrelated to or only distantly related to life on this planet.

      Now, of course, if life is silicon based, then you're right, you would have an
    • There is ample evidence that meteorites found in Antarctica have their origin on Mars. I wouldn't be terribly surprised if, in the event that indications of life are found elsewhere in the solar system, it turns out to be similar in many ways to life on Earth.

    • Re: (Score:2, Informative)

      by Jodaxia (312456)
      Well basically any carbohydrate would be good evidence of life, however cellulose just happens to be very stable. (Think cotton shirts, cows chewing cud, and metamucil.)

    • The real reason we want to explore Mars?

      Because we can

      or, a variant after my favorite mountaineer (after the late Edmund Hillary):

      Because it's there

      Stopping us from dreaming will make humanity dull and suicidal. Even though none of us might actually come to live the day that humans walk on the surface of Mars, doesn't mean that it is wrong to dream about it and start planning humanities future today.

      Don't hide in your house from wonderful things that
      • There's a real down-to-earth problem to this sort of attitude. Basic research, even in areas that may seem quite remote from anything practical, is absolutely key to advancement. You simply don't know in advance how basic research, whether it's some guy in the desert digging up dinosaur bones or lost cities, or a xenobiologist dreaming up new kinds of biochemistries, will ultimately aid humanity. To simply kill any research because one can't imagine an immediate benefit is a recipe for stagnation and los
      • The real reason we want to explore Mars?

        Because we can

        No you can't. It's millions of miles away. It's technologically possible to fire off an expensive rocket (hey, shit! it's not your money), but it's impossible to explore the place. The reports returned from the very expensive rockets that have been sent there indicate that the place is a dead dusty dry place. If it were 10,000 kilometers away from where you lived on earth, you wouldn't have any

        • Re:that's not the reason... (Score:5, Insightful)

          by ScrewMaster (602015) on Monday March 31 2008, @06:17PM (#22926114)
          To talk about space exploration and ignore real problems is to talk like a thief and a fool. Both of which we have too many of already. Grow up already and enter the real world.

          Well, it's a damned good thing the Queen of Spain didn't think like you.

        • Re: (Score:3, Insightful)

          by sofar (317980)
          I've got news for you:

                We *are* exploring Mars and we have been doing so for a long time already.

          Check your tax return this year and see how much money you paid into extraterrestrial research. You'll be surprised.

                "To talk about space exploration and ignore real problems is to talk like a thief and a fool."

          I guess all little boys who want to be astronauts on this world are thieves?

    • Re:So what else is new? No life on Mars. (Score:4, Insightful)

      by MightyMartian (840721) on Monday March 31 2008, @04:00PM (#22924878) Journal

      If you want cold lifeless desert, go to Death Valley or Arabia or the Gobi. It's much closer. You get the same empty experience, and, most importantly, you don't cost your fellow taxpayers any money.


      None of these, of course, are actually lifeless.

      • If you want cold lifeless desert, go to Death Valley or Arabia or the Gobi. It's much closer. You get the same empty experience, and, most importantly, you don't cost your fellow taxpayers any money.


        None of these, of course, are actually lifeless.
        Also, only one of them is consistently cold.
                • They can't support human life. Yeah. Except, y'know, for the people that live there. Sure, they import water, but we could extract that at a higher energy expense from the air and deep watersheds. (Solar energy can provide that extra energy, while also providing shade under the solar panels to make cooling the water-storage area easier.) A self-sustaining community in an Earth desert is perfectly possible.
                  If the mars polar caps do contain water ice a human community on Mars is possible.
                  A self-sustaining h

    • Re: (Score:3, Informative)

      by PresidentEnder (849024)
      As others have said, the old cellulose isn't the oldest evidence of life on earth. It's the oldest biological material on earth. Fossils are just rocks, prettily shaped.
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