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Space Science

Scientists Look at Martian Salt for Ancient Life 116

Posted by ScuttleMonkey
from the would-you-like-fries-with-that dept.
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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Scientists Look at Martian Salt for Ancient Life

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  • by Geoffrey.landis (926948) on Monday March 31, 2008 @03:40PM (#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]
    • by Chris Burke (6130)
      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!
  • I am no botanist, so I have to ask a potentially dumb question: are there any kind of cellulose-like variants that should be prospected as well?
    • 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 salt people!

    The salt people who?


    The salt people who left this solar system eons ago!

    :-)
  • D.E.L.I.C.I.O.U.S. !
  • by cowscows (103644) on Monday March 31, 2008 @03:47PM (#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.
  • Return Sample? (Score:5, Informative)

    by Gat0r30y (957941) on Monday March 31, 2008 @03:48PM (#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?
    • Re: (Score:3, Funny)

      by Tablizer (95088)
      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 @04:26PM (#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&gmail,com> on Monday March 31, 2008 @04:55PM (#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.
            • by Tablizer (95088)
              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 may start out in say the antarctic, but spread (evolve) to other environments over time fairly quickly because it has no natural enemies yet. It's similar to invasive species that beat out the native ones and become pests (like rabbits in Australia or the loud tree frogs in Hawaii). Its not that the invasive species is necessarily "bette
              • 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
                • by Tablizer (95088)
                  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.

                  Most living things on earth eat organic proteins and to a lessor extent sugars. It is somewhat likely that predatorial Mars life does the same. At least we cannot bet our safety on certainty it is different. "Probably" does not cut it.

                  If there was a common ancestor between life on Earth and some hypothetical Martian life
                  • by lorelorn (869271)
                    You are inventing non-existent risks, supplying meaningless numbers to these non-existent risks, and then saying we shouldn't do important research work for fear of your made-up risks.

                    You'll forgive us for ignoring you, it's the only sane response.

          • 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
            • by Tablizer (95088)
              I'd wager that ...

              You can say that with a million-to-one certainty? I don't think so. That is being overoptimistic about human science. Even our top theories are not that strong.

              We couldn't even prevent the housing bubble even though it was partially forcasted by many. You are going to trust human life to the same buerocrats? Please no!
                   
              • 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.
        • Re: (Score:3, Interesting)

          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
        • by Tablizer (95088)
          If even the first or second "unlikely" item on your list turns out wrong, it will cast doubt on our ability to estimate such things (assuming we trust them in the first place).
                 
    • by primenerd (100899)
      Not necessarily, there are several old-school biochemical techniques which can assay for cellulose (involving all kinds of fun acids!). Preparing a sample for EM is quite involved. Also, a heavy metal is necessary as a contrasting agent making sample preparation a decidedly destructive process.

      Personally, if I was going to design an assay for material of biological origin I would use the properties of chirality. All complex biological molecules have a handedness. Organic molecules of abiotic origin are a "r
  • 250 million? (Score:3, Insightful)

    by Tablizer (95088) on Monday March 31, 2008 @03:49PM (#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.

           
  • by mck9 (713554) on Monday March 31, 2008 @03:49PM (#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.
  • wtf? we can look at huge bones older than this?
    • Re: (Score:3, Informative)

      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.
      • by zakeria (1031430)
        your over stating ... so fossils are not evidence of life? ... ummm
        • No, fossils no longer contain any organic material. They're just fancy rocks that USED to be organic. This cellulose still IS organic.
  • 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 @03:53PM (#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.

    • by Punko (784684)
      Earth is our planet, while earth is a substance. One is a proper name, the other is a generic term for soil. Having said that, parent is correct that when we say "found on Earth" is should be capitalized. If the phrase was "found in the earth" either version could be correct, depending upon context.
    • Re: (Score:3, Insightful)

      by MightyMartian (840721)

      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!!
        • by jamstar7 (694492)
          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].
      • by bryguy5 (512759)
        Not really an answer to your question - mostly the big 3 don't address it. But I would reccomend reading C.S. Lewis Space Trilogy. This little fictional story does a neat job integrating extraterrestials and ancient pre-christian stories into a neat package. Gives a good example of something a quick-thinking clergy man might do.

    • 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

    • by Tablizer (95088)
      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.

      Most religions don't really address that. But if they find life and it's not [fill in the blank sect], then its "of the devil" and will probably be zapped.
           
    • by icebrain (944107)
      I seem to remember reading that the Catholic Church (at least) is open to the idea of life elsewhere. The big debate comes with intelligent life: are the aliens Saved?
    • 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.
    • by Kymermosst (33885)
      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 doubt we are alone. The real question is, are we alone with regard to how we have evolved with regards to intelligence and communication. After all, life on a distant planet is nothing but a small curiosity for scientific
    • I can't see why those particular religions would be concerned by the discovery of alien lifeforms - after they all centre around our own relationship with God and don't really focus upon the relationship God has with other, non-sentient life forms - nor indeed other hypothetical sentient forms of life. I imagine the discovery of alien life forms could well be troubling for atheists though.

      • by mlwmohawk (801821)
        I imagine the discovery of alien life forms could well be troubling for atheists though.

        I don't understand this statement, please explain. I'm an atheist and I can't imagine why it would be troubling.
  • Slug! (Score:3, Funny)

    by Tablizer (95088) on Monday March 31, 2008 @04:00PM (#22924322) Homepage Journal
    So my fantasy about pouring salt on a giant Mars Slug to save the astronaut colony still holds hope.
    • by jamstar7 (694492)
      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...
  • Stramenopiles (or heterokonts) [wikipedia.org] have incredible supporting evidence as having been on the planet for ~3 billion years. Here is a recent article from Nature [nature.com] and their editorial summary: [nature.com]

    Stromatolites are living, layered structures formed in shallow waters by a combination of microbial biofilms -- usually of blue-green algae -- and granular deposits. They are rare today but for about 2 billion years, following their arrival in the fossil record 3.5 billion years ago, they are the main evidence of life on Earth. Modern stromatolites still look like their fossilized forebears. But are the modern microbes remnants of ancient ecosystems or just latecomers following a similar lifestyle? A metagenomic study of the bacteriophage communities in modern stromatolites and thrombolites (like stromatolites but with an irregular internal structure) shows that stromatolite-associated phages are very different from each other and from any other ecosystem studied so far. This finding strengthens the hypothesis that modern stromatolites are remnants of ancient ecosystems.

  • Why? (Score:3, Insightful)

    by rrohbeck (944847) on Monday March 31, 2008 @05:13PM (#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
    • by hyades1 (1149581)
      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.
    • We don't know how many templates there are for life or the frequency of them. For all we know life follows a very similar chemical pattern everywhere it ariese. Or not. That's the point. We don't know, but it's worth looking into.
  • since there don't appear to be any Martians left, I'd say they weren't worth their salt.
  • It is obvious why there is no life on Mars. The men made all the women go to Venus so they could watch football. Once they decided they needed women, they could not find Venus and refused to ask for directions.

Byte your tongue.

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