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Space Science

Mars Had Surface Water for Eons 499

Posted by michael from the splish-splash-i-was-taking-a-bath dept.
LukePieStalker writes "Far from being a one-time event, it now appears that surface water flowed on Mars for eons. Nasa has announced that, after descending down further into the Endurance crater, the Opportunity rover has found a 'razorback'. It is believed that this was formed by 'fracture fill' from the minerals in percolating water. Since this feature extends through several geologic layers, it argues for a long period of wetness near the surface. This would seem to substantially increase the chance that life once existed on the red planet."
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Mars Had Surface Water for Eons More

Mars Had Surface Water for Eons

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  • How long is an eon? (Score:5, Insightful)

    by strictnein ( 318940 ) * <strictfoo-slashdot@@@yahoo...com> on Tuesday July 20, 2004 @01:53PM (#9750697) Homepage Journal
    Is there an official length of time for an eon? I know it just means "An indefinitely long period of time" but when it comes to life developing the amount of time available is quite important.

    ... Eon is a very long period of time. Geologists refer to a Phanerozoic Eon which is about 550 million years long
    The Archaeon Eon lasted over 2.1 billion years.

    or is it:

    An eon is the period of time it takes for a universe to come into being and then disintegrate again.
    • I don't know about that, but

      "That is not dead which does eternal lie,
      and with strange eons even death may die."

    • Re:How long is an eon? (Score:5, Informative)

      by iamdrscience ( 541136 ) on Tuesday July 20, 2004 @02:01PM (#9750823) Homepage
      From Merriam Webster [m-w.com]
      1 : an immeasurably or indefinitely long period of time : AGE

      2 a usually eon : a very large division of geologic time usually longer than an era b : a unit of geologic time equal to one billion years
      So it looks like it's officially 1,000,000,000 years, but also a term for a really huge block of time.

      • Re:How long is an eon? (Score:5, Insightful)

        by Rei ( 128717 ) on Tuesday July 20, 2004 @02:06PM (#9750892) Homepage
        The problem is that the rovers are not equipped to be able to tell how old these rocks are - nor is it likely that any rovers any time soon will be able to do this sort of work. Labs that do radioisotope separation don't easily fit all of the categories ("small", "lightweight", "robust", and "self sufficient"), needed to send things to other planets. A sample return is a much more likely course before we can start dating these rocks.

        Now, we can tell *relative* dates fairly easily with these rovers, but absolute dates are going to be a problem just using the rovers. There are some cases where you don't need radioisotopic dating, but I doubt they'll prove very useful here.

    • Eon = Division (Score:4, Informative)

      by Valiss ( 463641 ) on Tuesday July 20, 2004 @02:04PM (#9750867) Homepage
      The longest division of geologic time, containing two or more eras. For example, an era where Mars had water and an era afterwards, where there was no water.
      • The longest division of geologic time, containing two or more eras. For example, an era where Mars had water and an era afterwards, where there was no water.

        Well what constitutes an era? Who's to say that there were not subdevided eras when Mars had water? From what I see, your example is akin to saying that there has only been one eon on Earth: an era without life and an era with life.

        Besides, I tend to give a little more credence to the dictionary definition posted above.

    • Re:How long is an eon? (Score:5, Funny)

      by JustDisGuy ( 469587 ) on Tuesday July 20, 2004 @02:21PM (#9751123)
      It's as long as Slashdotters will argue over how long an actual eon is, when the reporter that used the term just thought it sounded good...

    • Re:How long is an eon? (Score:4, Funny)

      by sdo1 ( 213835 ) on Tuesday July 20, 2004 @03:27PM (#9751951) Journal
      How long is an eon?

      Ask Universe Man. He's got a watch with minute hand, millenium hand, and an eon hand.

      -S

  • Mars (Score:4, Interesting)

    by Luigi30 ( 656867 ) on Tuesday July 20, 2004 @01:53PM (#9750700)
    So does this mean that we might be able to find traces of water and/or life if we keep digging, or that the water is all gone?

    • Re:Mars (Score:3, Interesting)

      by Jim Starx ( 752545 )
      If there was life then the right kinds of test should be able to find traces of it. I wonder if they've got the right stuff for the tests on the rover. There's only so much you can fit on that thing.
      • Remember the scene in Raiders of the Lost Arc where it get's crated up and put in Top Secret storage? Same thing with life on Mars. Do you really think that George Bush (Mr. Fundy Christian) would allow this cat out of the bag? Stop pointing at my tinfoil hat.

      • Re:Mars (Score:5, Informative)

        by Rei ( 128717 ) on Tuesday July 20, 2004 @02:43PM (#9751413) Homepage
        They already did that on Viking. The results were inconclusive, but suggestive of abiotic processes. The tests were as follows:

        GEX (Gas EXchange experiment): Looked at gas level changes in martian soil vs. a control which it sterilized first.

        LR (Labeled Release experiment): Looked for uptake of a radioactive liquid by gas presence, again vs. a control which it sterilized first

        PR (Pyrolytic Release experiment): Like the LR, but in reverse; cooked the samples afterwards to see if they uptook radioactively tagged CO2.

        GCMR (Gas Chromatograph - Mass spectRometer experiment): Heated soil samples and did a spectral analysis of them.

        First, GCMR's results: Found an unexpected amount of ice, but found surprisingly *little* organics, leading scientists to conclude that some process was *destroying* organics on Mars.

        For the others, the following would have been expected from each if there was life:

        GEX, sample: O2 or CO2 released
        GEX, control: No release
        LR, sample: Labelled gas emitted
        LR, control: No release
        PR, sample: Carbon detected
        PR, control: None

        If there was no life, both samples and controls were expected to be the same. The real results?

        GEX, sample: O2 released
        GEX, control: O2 released
        LR, sample: Labelled gas emitted
        LR, control: No release
        PR, sample: Carbon detected
        PR, control: Carbon detected

        In short, it was confusing, but was believed to be related to abiotic processes.

    • Re:Mars (Score:5, Informative)

      by Rei ( 128717 ) on Tuesday July 20, 2004 @02:08PM (#9750930) Homepage
      We know there's still water there; unfortunately, it's in the form of ice.

      As for fossils or traces of life... who knows? All we can say is that Spirit and Opportunity aren't going to be finding it unless it's macroscopic. They can only dig centimeters deep, and don't have the sort of magnification needed to see microscopic organisms.

    • Re:Mars (Score:5, Interesting)

      by cephyn ( 461066 ) on Tuesday July 20, 2004 @02:20PM (#9751116) Homepage
      Well there's multiple scenarios. First, there's the estimated amount of water that would cause the global areological features. Take that number, and subtract the estimated amount of water locked in ice at the poles -- we can estimate this through satellites. The North Pole is mostly water ice, South is mostly dry ice.

      Now, that leaves a Heckofalot of water. (A Heckofalot is an official measurement, look it up. It's just short of a Hellofalot) Anyway, that water could be underground...perhaps in shallow aquifers, perhaps quite deep. It's hard to say, we just don't have the tools yet. Then there's the portion that would have been lost. Martian gravity is lower than Earth's, so it couldn't hold as thick an atmosphere as we do. So some water might have just evaporated off the entire planet. Also the Martian magnetic field is quite weak -- perhaps it was stronger before (there is some evidence for that) but when it weakened, it would have allowed solar wind and radiation to rip away the atmosphere and carry water vapor with it.

      In short (ha) If we keep digging, we may find none, a little, some or a lot of water.

      • Re:Mars (Score:3, Funny)

        by PornMaster ( 749461 )
        First, there's the estimated amount of water that would cause the global areological features

        Areological? Mars has areolae? I thought that was Venus.

        -PM

  • Fantastic! (Score:2, Funny)

    by Limburgher ( 523006 )
    Now we just need to evidence of other university mascots, and we can build a case for a Mars Bowl.

  • Water common? (Score:5, Interesting)

    by lecithin ( 745575 ) on Tuesday July 20, 2004 @01:54PM (#9750717)
    If we can confirm that there is/was water on Mars, what does this say about the rest of the Universe? Is water all that common? If we then associate water with the chance of life, out of the billions of stars, we just ain't alone. Insert Overlord comments below.

    • Re:Water common? (Score:5, Informative)

      by LeahofRivendell ( 797671 ) on Tuesday July 20, 2004 @01:59PM (#9750792) Journal
      Is water all that common?

      Not only is water uncommon, the liquid phase is uncommon. Also, the reason it's so important is because it is less dense in the solid phase than the liquid phase, which allows it to freeze on top instead of on bottom, which in turn allows organisms to sustain life even when the body of water begins to freeze.

      • Re:Water common? (Score:5, Interesting)

        by Artifakt ( 700173 ) on Tuesday July 20, 2004 @02:10PM (#9750975)
        To expand on Leah's comment - There are other liquids that are very simple atomically so they exist a lot around the universe. Two of these are Methane and Ammonia, both liquid under some circumstances. Because they are not polar molecules, the range they stay liquid is much narrower than for H2O. Their ice form is denser than the liquid, so lakes or oaceans of them will freeze from the bottom up, and there won't be an insulating layer to keep them from freezing over completely. So not only life as we know it, but some of the alternatives that we guess just might be possible are affected. Ammonia based life would only be possible in environments with a colder AND much narrower temperature range than Earth's. Freezing winters would be a critical problem instead of something life might be able to adapt around.

        • Re:Water common? (Score:5, Interesting)

          by Rei ( 128717 ) on Tuesday July 20, 2004 @02:32PM (#9751283) Homepage
          This requires a couple of assumptions:

          1. Life can't exist in high-pressure environments.

          Higher pressure environments have much wider ranges for the liquid phase of ammonia and methane.

          2. Life cannot develop on planets with freeze/thaw cycles.

          I see no reason why this should be the case. In fact, with methane and ammonia, you don't have to worry about cells being ruptured by freezing, so long as they don't have stiff cell walls.

          Further, a "cell" is not the first life; you first have molecules that tend to catalyze the production of "similar", if not exact, molecules. The processess regionally take off. Groups of molecules that more accurately catalyze the production of their member molecules form "hypercycles" - regions which, while not distinct from each other, catalyze their own development. As these hypercycles begin to become distinct and compete with each other, they end up being walled off into "Ur-cells/Protocells" (depending on your terminology).

          At least, that's one theory I've seen presented, which seems reasonable.

          3. It is not hotter near the bottom.

          There is no particular reason to expect this. In fact, in many environments in the universe where we expect there to be liquid, this is exactly what we expect; geothermal heating, tidal heating, precipitative convection heating, etc.

          4. There are no dissolved molecules that can act as "antifreeze"

          Pure solutions of methane or ammonia are unlikely.

          5. Life requires a liquid solvent to develop.

          While this is probably true, we don't know this for sure yet.

        • Re:Water common? (Score:3, Informative)

          by markmier ( 306777 )
          Ummmm... ammonia is quite polar. NH3 dipole moment is 1.5 D. Water is 1.8 D. (methane is indeed nonpolar).

          At 1 atm pressure, ammonia melts at -108F, and boils at -28F (from GPSA handbook). So it has an 80F range of liquidity, whereas water has 212F. However, like you said, ammonia solid is more dense than the liquid. Water is one of only a very few materials (gallium is another, I can't remember any others but I bet there are some) that are more dense as a liquid.

          By comparison, methane melts at -2

          • Re:Water common? (Score:3, Interesting)

            by Artifakt ( 700173 )
            NH3 Polar, well, yes, as you point out, but if you don't mind me qualifying it a bit, I'd say NH3 isn't usefully polar, in that it doesn't have the equivalent of Van der Walls forces between liquid molecules at a strength sufficient to much help stretch the range of liquidity (a tiny bit, but not much). The 2 Hydrogens in a water molecule don't line up on the opposite sides with the oxygen atom in the middle, but form a rather pronounced bend. By contrast the three hydrogens in Ammonia don't leave the Nitro

            • Re:Water common? (Score:4, Interesting)

              by Xilman ( 191715 ) on Tuesday July 20, 2004 @04:16PM (#9752619) Homepage Journal
              NH3 Polar, well, yes, as you point out, but if you don't mind me qualifying it a bit, I'd say NH3 isn't usefully polar, in that it doesn't have the equivalent of Van der Walls forces between liquid molecules at a strength sufficient to much help stretch the range of liquidity (a tiny bit, but not much).

              By a hell of a lot, actually. Compare its liquid range with methane, which has essentially the same molecular weight (CH4 = 16, NH3=17, H2O=18).

              NH3 is also usefully polar in that it allows a good many salts, acids and bases to disolve in it, again like H2O. Methane doesn't.

              The 2 Hydrogens in a water molecule don't line up on the opposite sides with the oxygen atom in the middle, but form a rather pronounced bend.

              Correct.

              By contrast the three hydrogens in Ammonia don't leave the Nitrogen sticking out by itself. They may not maintain perfect 120 degree angles in a flat plane around the N's "equator" under all conditions, but they are pretty close to it.

              Incorrect. The NH3 molecule is substantially pyramidal. The H-N-H angle is close to 107 degrees [avogadro.co.uk]It's the flipping between the pyramidal configurations that's the basis for the ammonia maser. (Actually, it isn't, really, but unless you want a digression into molecular quantum mechanics that explanation is good enough and will have to do.)

              Now as regards life forms, what applies to a relatively pure liquid is more than usually not something we can extrapolate too much to a mixture, so I wouldn't read too much into it. Our one example of liquid oceans is not exactly pure H2O, after all, and showing that there are some reasons life is less likely in close to pure Methane or Ammonia doesn't limit a lot of other possibilities.

              Good! It is extremely unlikely that an ocean would be pure ammonia, any more than our oceans are pure water. It's rather likely, I suggest, that a predominantly ammonia ocean would contain a large amount of disolved water, which would raise the liquid range and make the chemistry both different and probably more interesting from a biochemical point of view.

              Paul

      • Re:Water common? (Score:5, Informative)

        by Rei ( 128717 ) on Tuesday July 20, 2004 @02:14PM (#9751026) Homepage
        "Not only is water uncommon, the liquid phase is uncommon"

        That should have read:

        "Water is not uncommon; only the liquid phase is."

        Our solar system is jam packed full of ice. Heck, Uranus and Neptune are best described as "Ice Giants" instead of "Gas Giants", due to their expected ice cores. Ice dominates the moons in the saturnian system, the kupier belt and oort clouds are composed mostly of ice, etc, etc. In fact, it is even theorized that Earth got its water from comets.
      • Not only is water uncommon, the liquid phase is uncommon.

        Water is likely very common. Hydrogen in the most common element in the universe, and Oxygen is a pretty common element as well.

        The liquid phase of water appears to be fairly uncommon, in our solar system and likely everywhere.

    • Re:Water common? (Score:5, Informative)

      by AKAImBatman ( 238306 ) <akaimbatman@g m a i l . c om> on Tuesday July 20, 2004 @01:59PM (#9750796) Homepage Journal
      Water should be pretty common near stars as Hydrogen is the fuel which runs them. When combined with oxygen pulled near the star by gravitation, you find yourself with water. The difficulty is in finding it in liquid form. Planets and planetoids near a star will have their water blown or boiled away. This water will then travel toward the outer system. If no large body exists in the star's "temperate zone", then the water will continue on. If it hits a body outside of the "temperate zone", it will remain as ice.

      At least, that's how I understand it.

    • Re:Water common? (Score:5, Interesting)

      by Ra5pu7in ( 603513 ) <ra5pu7in@@@gmail...com> on Tuesday July 20, 2004 @02:04PM (#9750857) Journal
      I had that same sort of thought. Confirmation that flowing water existed on Mars, even if none remains today, coupled with the number of asteroids / comets that have ice does tend to imply water is reasonably common in our universe. Two planets within a certain size range and within a certain distance of their star both having had water seems a better argument for the existence of water on other planets around other stars. (No Overlord comment - it would just confuse the puny humans I am controlling.)

    • Re:Water common? (Score:5, Insightful)

      by pclminion ( 145572 ) on Tuesday July 20, 2004 @02:09PM (#9750961)
      Is water all that common?

      Probably yes. Hydrogen and oxygen are among the most abundant elements in the universe.

      The unusual thing about Earth is that the environment is at the triple point of water. Water is able to exist as a gas, liquid, and solid all together in the same environment. This is only possible in a narrow range of temperatures and pressures. So water is probably very common. Liquid water, OTOH, is not.

      As for why water is important for life, see one of my older comments [slashdot.org].

    • Why water? Many Sci Fi authors have predicted life cycles based on other substances, in various and other temperature gradients. Ammonia, liquid nitrogen, copper based (as vs. iron), crystal matrix, fluid dynamics in a methane bubble of a gas giant, Orrt Cloud dust mote patterns, etc. have all been used as life origin foundation platforms. To limit "life" to only those chemical reactions involving the ash of burnt hydrogen and its reaction with carbon, silicon, and strange amino acids is pure chemical/th

      • Re:Water common? (Score:3, Interesting)

        by Rei ( 128717 )
        I'll second this. I once was debating with someone over whether silicon-based life was possible, and as I researched, I was actually surprised by the chemical complexity available in silicon compounds. Silanols, for example, are found all over in Earth's oceans, and can form sheets, catalyze reactions, and all sorts of other things. While your basic "silicone" is pretty simple (chains of Si-O-Si-O... etc), so is your basic N-ane hydrocarbon chain. What makes organic chemistry interesting is functional g

        • Re:Water common? (Score:3, Interesting)

          by gamgee5273 ( 410326 ) *
          Carl Sagan, in Cosmos, believed that, when (and yes, he was a firm believer of when) we encounter life on another planet we should not be surprised if we find silicon-based life.

          Popular imagination doesn't think of alien lifeforms as anything other than carbon-based (see almost any popular SF TV show in the past 40 years) or cyborgs (the Borg in Star Trek, of course). The best example of a silicon-based lifeform in popular fiction is the xenomorph (the aliens) from the Alien and, frankly, the fictional b

      • Re:Water common? (Score:4, Informative)

        by Pharmboy ( 216950 ) on Tuesday July 20, 2004 @03:10PM (#9751760) Journal
        Why water? Many Sci Fi authors have predicted life cycles based on other substances, in various and other temperature gradients.

        I think the main point here is that we know that life can grow where there is water, and we have some pretty good ideas what to look for. For instance, we are looking for proof of water on Mars, and then we know to look where the water USED to be in order to find where life MAY have been.

        When it comes to life that isn't carbon based and/or came from water, we simply don't know what to look for. We could be looking right at it and not see it because we have no point of reference, no experience, no tell tale signs that say "life was/is here". That doesn't mean life doesn't exist without water (or without being carbon based). It just means we would be unlikely to understand what we found with the limited tools on a probe unless the think came up and started waving "hi" to us.

        Considering that water is relatively common in the areas of the solar system that we would THINK there could be life (venus thru mars + moons of outer planets), the smartest investment we can make is to look for the kind of life we know can exist, where we think it can exist. This means where liquid water is or was.
    • In other news, it has been found that previous Mars rovers that have dissappeared onto the martian atmosphere have been sent back eons in time due to a glitch in calculations of relativity. The failed rover landed in a creater and had a fuel leak, with the spilliage causing creavases in the land called 'razorbacks'.

  • Why is it surprising? (Score:4, Insightful)

    by Neil Blender ( 555885 ) <neilblender@gmail.com> on Tuesday July 20, 2004 @01:55PM (#9750736)
    If Mars had water, why would it not have it for a long time?

    • Re:Why is it surprising? (Score:5, Interesting)

      by xenophrak ( 457095 ) on Tuesday July 20, 2004 @02:03PM (#9750849)

      I think the common dogma is that a catastrophic event happened some billion years ago where Mars lost its magnetic field. The loss caused the upper atmosphere to be evaporated from solar radiation that was then allowed to pass into the lower levels.

      One might surmise that since the Earth has a molten fluid core and routinely undergoes magnetic reversal that Mars once had the same type of core, but it may have cooled and solidified, rendering the field inoperable.

      Whatever it's worth, I think that the ammonia presence is far more interesting than the traces of water.
      • What would ammonia signify??

        • Re:Why is it surprising? (Score:5, Interesting)

          by Cecil ( 37810 ) on Tuesday July 20, 2004 @02:29PM (#9751238) Homepage
          A significant amount of ammonia in the atmosphere that has not been broken down by solar radiation would signify that it is being generated on the planet currently. The only two methods we know of that would produce enough ammonia to be detected are active vulcanism, specifically an active volcano somewhere, which we have never seen, or microbial life. I suspect the original poster is more excited about the latter possibility.
    • If it turns out that it had water for billions of years I would call that a long time.

      Just because we don't see it now doesn't mean it was short lived. Remember that dinosaurs lasted much much longer than humans have so far.

  • On 20th July too. (Score:3, Funny)

    by Skiron ( 735617 ) on Tuesday July 20, 2004 @01:55PM (#9750742)
    Shame them didn't actually find water today of all days - 20:17:43 20 July 69 [nasa.gov]

  • Chances of Life (Score:3, Interesting)

    by Dominatus ( 796241 ) on Tuesday July 20, 2004 @01:57PM (#9750758)
    I don't quite see the obession with finding life on Mars.

    In terms of science, we know it's possible, it's not an issue of "can" it happen it's an issue of "where" did it happen again. We also know that if there was life it's doubtful it went beyond the microscopic range as not only is there no evidence of that, but life existed on this planet for eons w/o going past the microscopic range. It's arguable that the natural result of life is not always complexity and size.

    It seems to me the only reason people are obessed with finding life on Mars, or anywhere else for that matter, is to fill some urge that if they do, to less scientific minded (read: religious) people will be proven wrong.

    • Re:Chances of Life (Score:5, Interesting)

      by QEDog ( 610238 ) on Tuesday July 20, 2004 @02:03PM (#9750844)
      I don't quite see the obession with finding life on Mars.Because by finding life somewhere else we can learn a lot about life on earth.

      What is life? Really? You will find many people with slightly different definitions just on life on Earth.

      What about other planets? What if life in mars, the DNA strand twists the other way? Or what if there is no DNA. If the DNA is the same, then, maybe life in Mars and Earth have a common origin. If not, what common things do we see? What is the minimum requirement for life? And these are just a few questions I can speculate on. I think we can lear about ourselves, and the fundamentals of life on Earth by finding life somewhere else.

      And that is all without any religious (or anti-religious) agenda.

    • How do we "know" that it didn't go beyond the microscopic level? Take a rainforest, insert cataclysmic event or two (or even drastic climate change), wait a few million years- now tell me what signs would be visible from the surface of the rainforest? I would gather that there would be not one sign whatsoever from the surface let alone from satelitte imagery.

      I think that the interest lies in the possibilities- if this solar system had two (minimum) planets with life then #1 earth is not such a freak a

    • Re:Chances of Life (Score:2, Insightful)

      by mr_pins ( 694549 )
      I don't think so. Even if I grant that "we know it can happen", the bigger question is "How likely is it to happen?"

      Finding evidence of life on Mars would be extremely helpful/interesting in begining to answer this question. I'd say that is the main reason people are so "obsessed" with finding life on Mars.

    • Re:Chances of Life (Score:4, Insightful)

      by lukewarmfusion ( 726141 ) on Tuesday July 20, 2004 @02:09PM (#9750944) Homepage Journal
      I know scientists that believe such a discovery would discredit religious beliefs... but many religious folks I know have absolutely no problem with life on other planets (or some a source other than that described in the Creation story).

      One friend of mine, a pastor at a non-denomination church, argues that the Creation story is not a literal history; science can never remove God completely, no matter the discoveries.

      Really, the obsession with life on Mars (or other places) has a lot of sources. As we learn more about the Universe, human beings don't want to be alone in it. We want to try and answer questions that may not have answers here on Earth, including the origins of life and the nature of evolution. Wouldn't you like to be there to witness the natural beginning or end of life on an entire planet?


      • > I know scientists that believe such a discovery would discredit religious beliefs... but many religious folks I know have absolutely no problem with life on other planets

        Religion is compatible with any discovery - iff you want it to be.

      • Re:Chances of Life (Score:3, Interesting)

        by jdavidb ( 449077 )

        I'm a literal (6000-year) creationist, and I fail to see how the Creation rules out life on other planets. It just isn't in the original text, although I suppose a lot of people (both religious and non-religious) have tried to read it into it.

    • Re:Chances of Life (Score:3, Insightful)

      by Sloppy ( 14984 ) *

      In terms of science, we know it's possible, it's not an issue of "can" it happen it's an issue of "where" did it happen again.

      But if you find it, you also get to ask how it works. Imagine what finding life, especially if it turned out to be unrelated to Earth life, would do for biochemistry. Life implemented without the usual DNA/RNA, or implemented with different encodings or whatever, would be pretty neat to study. Probably all sorts of applications, too.

      It seems to me the only reason people are obe

    • Re:Chances of Life (Score:3, Insightful)

      by namidim ( 607227 )
      First, since when does the presence of life on other planets contradict the existence of a god? The earth isn't flat and the sun doesn't orbit us either, yet somehow world religions go on. Second, how is it so hard to see the innate value and magnitude if we were to discover life on mars? Finally, why is the discovery of life only interesting if it involves little green men. Microbial life on mars would be a watershed event in it's own right. I can't even begin to list all the medical, philisophical, biolog

    • Re:Chances of Life (Score:5, Insightful)

      by DynaSoar ( 714234 ) * on Tuesday July 20, 2004 @02:19PM (#9751094) Journal
      "I don't quite see the obession with finding life on Mars."

      I do. But then I'm a scientist. I want to know stuff. I want to know as much as possible, and have other people in other fields find out as much as possible, because you never know what good things that can improve the quality of life can come of it. And actually, that last part is justification so that society will continue funding my research. Mostly, I just want to know stuff. It's why I became a scientist.

      Also: because that's what humans do. They explore. They want to know their environment. I could probably come up with a decent hypothesis regarding cognitive dissonance driving humans' desire to decrease the number of unknowns in their environment in order to maximize their comfort level and probability of survival. But then that's the other thing I do as a scientist. Come up with hypotheses. Fact is, for whatever reason, or maybe no reason other than evolutionarily determined hard wiring in the brain, it's what people do.

      Anyone not interested is free to focus their attention elsewhere. And dollars to donuts they themselves will have something like this that drives them that other people may not understand.

      I'm sure you're right, that some people would use such a discovery as proof for and/or against some religious viewpoint. Hell, they did it with rock and roll music, and pretty much anything you can think of that they can use as leverage against each other in their power games. Good for them. Everyone needs a hobby, it gives them purpose in life, and it keeps them out of my hair.

      • Re:Chances of Life (Score:3, Interesting)

        by Sgt York ( 591446 )
        Mostly, I just want to know stuff. It's why I became a scientist.

        Reminds me of a fortune I saw once. "As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life - so I became a scientist. This is like becoming an archbishop so you can meet girls."

        It rings so true for a grad student in the doldrums of the 4th year.....

        But I still just want to know. It's a curse. If my PI would let me pursue all the tangents I want to pursue, I'd be here for

    • Re:Chances of Life (Score:3, Insightful)

      by KevinKnSC ( 744603 ) *
      In terms of science, we know it's possible, it's not an issue of "can" it happen it's an issue of "where" did it happen again.

      Part of the fascination is that we don't know if it's possible. We think that it might be, and the odds seem to be in favor of it, but we won't know for sure until we find some evidence of it. That's how science works.

      It seems to me the only reason people are obessed with finding life on Mars, or anywhere else for that matter, is to fill some urge that if they do, to less scie

      • Re:Chances of Life (Score:2, Insightful)

        by Dominatus ( 796241 )
        "Part of the fascination is that we don't know if it's possible. We think that it might be, and the odds seem to be in favor of it, but we won't know for sure until we find some evidence of it. That's how science works."

        We do know it's possible, evidence is right in front of you. Earth. Earth isn't some magical existence according to science, it's just a planet. If it can occur then it will occur, and given enough time it must occur.
    • The reason it's an 'obsession' is because (to paraphrase Heinlein's 'Number of the Beast'), two is such a ridiculous number.

      What that means is that, right now, we have no empirical evidence that life exists anywhere but on earth. If we can find life on another planet or non-earth object, then there stands a good chance that life is fairly ubiquitous throughout the cosmos (at least in terms of being homogenously dispersed through all of the environments that can support it).

      That, of course, assumes that

    • Re:Chances of Life (Score:5, Interesting)

      by Kphrak ( 230261 ) on Tuesday July 20, 2004 @02:38PM (#9751356) Homepage

      I've never understood the thinking that if life was found on another planet, all religious people's (they mean "Judeo-Christian and maybe Islamic", not "religious") heads would explode, and God Himself would vanish in a puff of logic. What's to stop God from creating life on another planet?

      The idea that Earth was the center of the universe originated with some Greek philosophers (Aristotle and Ptolemy were among these), and the idea was actually quite controversial even then. The only reason why it became canonical (plenty of Christian scientists, including Johannes Kepler, argued against it) was that it was one of the few things left from the ruin of the ancient world by the time monastic scribes got hold of it, and the ancients were so impressive that it was hard to imagine anyone one-upping them at the time. Such a theory is never mentioned explicitly in the Bible, and it's pretty doubtful that any religious person would care about its collapse. Unless there are still Christians who believe that the orbit of any planet can be described by a perfect circle...

  • of course, science fiction never fortells the future now, does it...
  • razorback
    • n 1: thin-bodied mongrel hog of southeastern United States that is a wild or semi-wild descendant of improved breeds [syn: razorback hog, razorbacked hog]
    • 2: any of several baleen whales of the family Balaenopteridae having longitudinal grooves on the throat and a small pointed dorsal fin [syn: rorqual]

    Yep, I guess that would be proof of water.

  • IMO the rovers have done well in proving the prior existence of water.

    In the now "urgent" perogative of human visitation of Mars, an interim step sending larger rovers capable of sub-surface graphing would aid the future landings in prospective dig sites.

    Plus it gives Val Kilmer time to build his robotic dog.

  • Still waiting for fossilized remains. (Score:5, Insightful)

    by LeahofRivendell ( 797671 ) on Tuesday July 20, 2004 @02:03PM (#9750850) Journal
    To me, that's the only concrete proof of life on Mars. Life is complex--there's more to it than water.
  • simply because there are giant chunks of ice that have been visible on its surface for as long as I have been alive. Where there's smoke...
  • I scan the raw feeds from Mars regulary. I ran across the following image: Mars Photo [nasa.gov]. Now if that doesn't significantly improve the odds of life on Mars I don't know what does.

  • Another possibility (Score:4, Interesting)

    by techno-vampire ( 666512 ) on Tuesday July 20, 2004 @02:08PM (#9750934) Homepage
    If water is dripping into a gap caused by a fault, it might not take that long for dissolved minerals to fill the hole. Considering how big stalactites and stalagmites can get in a few thousand years with just a slow drip, how long would this take with periodic flooding followed by a long dry spell?

  • Can't increase chances retroactively (Score:3, Insightful)

    by ColonelPanic ( 138077 ) on Tuesday July 20, 2004 @02:09PM (#9750943)
    This would seem to substantially increase the chance that life once existed on the red planet.

    No. Life did or did not exist on Mars, but either way, its chances are over.

    What these results might increase, if true, is the chance of our discovering evidence that life has existed on Mars.

    • Re:Can't increase chances retroactively (Score:5, Insightful)

      by fiannaFailMan ( 702447 ) on Tuesday July 20, 2004 @02:27PM (#9751212) Journal
      Okay then. It "increases the chances that it is true that life once existed on Mars." Happy now?

    • Re:Can't increase chances retroactively (Score:5, Insightful)

      by ViolentGreen ( 704134 ) on Tuesday July 20, 2004 @02:39PM (#9751365)
      Is it seriously necessary to pick apart posts and respond on technicalities? I don't think there is really much doubt about how the comment was meant. The meaning came across fine.

      This remindes me of those exercises that I did in grade school where I had to write specific instructions on how to make a peanut butter and jelly sandwich. The teacher would then make a mockery of the instructions by making a mess with the ingrediants.

      Few people here are lawyers so few statements are going to be hole free. Most statements here and elsewhere in the world require a little common sense to interpret correctly.

      Being excessively anal accomplishes nothing.

  • too bad Mars didn't have more mass (Score:3, Interesting)

    by frankie ( 91710 ) on Tuesday July 20, 2004 @02:09PM (#9750959) Journal
    If only Mars had a deeper gravity well, it would still be wet today, and probably alive.

    Of course, if it were, either we would have gone there and slaughtered the natives already, or vice versa.

    Instead, Mars and Venus serve as object lessons on the narrow window [google.com] of planetary viability.

    • Not mass, magnetosphere (Score:5, Informative)

      by kippy ( 416183 ) on Tuesday July 20, 2004 @02:20PM (#9751115)
      Both Mars and Venus are bone dry because they have little to no magnetosphere. This allows water vapor to be broken into H and O by UV radiation and since the H is light, it can acheive escape velocity much faster when hit by unhindered solar wind.

    • If you switch Mars and Venus each would have a better shot (if they had better magnetospheres)

      Mars would be in more, but couldnt sustain the thick atmosphere of venus. It might be a greenhouse planet, but with a much thinner atmosphere I doubt it.

      Venus would be able to hold more of an atmosphere than Mars does, so at Mars orbit it would have a thicker atmosphere and less extreme temperatures. Sure, colder than earth, but not Mars cold.

      Its possible.
    • I thought it was the magnetic field, not the gravitational field that was too weak. Low magnetic field means no protection from solar wind which "blew" away the atmosphere and the water vaporized and blew away in the resulting vacuum. But IANA Planetary Geologist.

  • deeper (Score:2, Funny)

    by Doc Ruby ( 173196 )
    Searching for life on the Martian surface is asking two wrong questions. Because below the surface, Mars is teeming with UNDEAD vampires!

  • article mirror (Score:2, Informative)

    by Anonymous Coward
    Freecache of article image [freecache.org]

    Surface water on Mars existed across a significant span of time, not just for years but eons, suggest new findings made by NASA's Mars rover Opportunity.

    Within a few weeks of its landing on Mars in January 2004, Opportunity revealed what was uppermost on the twin rovers' agenda: that bodies of liquid water once existed on the surface of Mars. But the evidence proved what could have been only a solitary event - a single wet episode.

    The new discovery, reported by NASA's Jet Propu

  • My guesses about water and life on Mars. (Score:5, Interesting)

    by MtViewGuy ( 197597 ) on Tuesday July 20, 2004 @02:20PM (#9751117)
    Personally, I think that once Mariner 9 showed what is very likely former riverbeds on Mars, it's obvious that in the distant past, Mars had water and very likely some form of lower-level lifeforms.

    In my opinion, here's what happened on Mars:

    1. In the distant past when there was flowing water on the plant, life did evolve, with the likely chance that we had fairly advanced plants lifeforms and lower level animal lifeforms.

    2. Alas, when the atmosphere thinned, the surface water evaporated, essentially killing all lifeforms except for (at best) forms of bacteria and possibly algae that could survive in today's extremely severe Mars climate, living off the water trapped under the surface of the planet.

    3. I think when the Mars Science Laboratory lander/rover reachers Mars in 2009, it will find that life does exist on the planet today in the form of bacteria or something related to it.

  • Mars may tilt sideways for more extreme climate (Score:5, Informative)

    by peter303 ( 12292 ) on Tuesday July 20, 2004 @02:24PM (#9751186)
    Earth has a large moon which stabilizes the tilt angle of its rotation axis. The Earth bulges at at equator from its rotation and the pull of the moon. The moon pulling on this bulge keeps the earth's axis steepening much more than it is now- a 23-degree tilt. The tilt angle creates the seasons. If it tilted more, there'd be warmer summers and colder winters.

    Mars lacks a significant moon. Therefore people speculate that it could tilt all the way over on its side sometimes and have extreme seasons. Maybe even extreme enough to melt the carbon and water ices at the poles and permafrost.

  • Dynosaur skeletons and oil (Score:4, Interesting)

    by HermanZA ( 633358 ) on Tuesday July 20, 2004 @02:35PM (#9751317)
    That is all they need to find, to cause a new space race.

  • Existance of Life (Score:3, Interesting)

    by Harpua22 ( 738249 ) on Tuesday July 20, 2004 @02:39PM (#9751368)
    "This would seem to substantially increase the chance that life once existed on the red planet" I think a more accurate statement would be that this increases the chances that we might find evidence of carbon based life forms having existed at some point on mars. It is theoretically possible for life to exist without water by using another liquid solvent as a substitute. One often proposed substitute is ammonia (see article http://www.daviddarling.info/encyclopedia/A/ammoni alife.html/ [daviddarling.info] ). People seem to think narrowly about the possibilities of life, and often constrain their thought process to life that is, at a very basic level, similar to life on earth. Granted, since carbon is fairly prevalent throughout the universe there is certainly a good chance of it forming life in areas other than earth, but we should keep in mind that it is not (at least theoretically) the only option.

  • Slashdot Categories and Mars... (Score:3, Insightful)

    by rulethirty ( 673757 ) on Tuesday July 20, 2004 @02:51PM (#9751519)
    Aren't there enough articles about Mars to warrant its own category within Slashdot?

  • NewScientist Scoop? (Score:3, Interesting)

    by captainClassLoader ( 240591 ) on Tuesday July 20, 2004 @02:57PM (#9751588) Journal
    Well, this article is pretty fascinating, and not only for its content - None of the other [space.com] space [spaceflightnow.com] exploration [spaceref.com] sites I visit regularly seem to have this information - At most, they talk about Opportunity's discovery of the Razorback feature, but no discussion of analysis. Has NewScientist scooped everyone on this discovery, or was this publicized prematurely?

    No tinfoil required, really, just an observation.

  • Life IN Mars (Score:5, Interesting)

    by Randym ( 25779 ) on Tuesday July 20, 2004 @03:37PM (#9752063)
    This would seem to substantially increase the chance that life once existed on the red planet.

    Every planet probably has microscopic, non-oxygen-using life INSIDE it. (In fact, it may even be NON-microscopic.) Just because we don't find it lying about the surface does not mean that it did not exist.

    When we talk about 'life on earth' it's assumed that we are talking about life on the *surface* of Earth. But that surface is *7 miles thick* [depth of ocean] and the radius of Earth is *4000* miles. And we know non-oxygen-using extremophiles and Archaea exist *here*. Why not there?

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