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Space Science

Testing For Life On Mars 133

Posted by Hemos from the put-the-test-tube-here dept.
swestcott writes "This is a very interesting article in the Washington Post today about an experiment on the Viking mission to Mars apparently found life on Mars - or not."
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Testing For Life On Mars More

Testing For Life On Mars

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  • hi bliss (george here)

    i agree with you for the most part but must correct you on one part, carl sagan was not fictional, he actually did exist and wrote many books including contact and the demon haunted world. true he is dead now but that does not mean he never existed.

    your bud
  • Comment removed based on user account deletion
  • Because the trip from Earth to Mars, even when their orbits are closest, would take... what is it now, a year? (twenty years ago it was three years, but propulsion technology's advanced since then). It's not the same thing as having a shuttle in orbit of Earth - you can pretty easily send supplies over there. But a shuttle going to Mars will be too far away for it to be practical to send it supplies, so it will have to have them onboard - about 2.5 years' worth for however many passengers are onboard. Then there's energy concerns (we have to have enough energy and fuel to get there and back and survive) and oxygen problems (I know shuttles have oxygen recycling systems, but I'm not sure how efficient they are - obviously not 100% efficient, that's impossible).

    Then, of course, there's psychological stress - extreme boredom, etc.

    Need any more reasons?


    Nonexistent.
  • ...it also cost 10 times what missions in the current Mars exploration program do. And not all the current missions have been failures. All we need is 1/10 to succeed and we're still coming out even.
  • Well, I probably get some people irrtated about this. But for some it may be quite interesting to see. Besides this is another region of Mars - Tharsis

    http://ida.wr.usgs.gov/html/m07009/m0700934.html
    A probable "underground" river. Well I state it probable because I still didn't analysed it at full. Some may state this could be blown dark sands. However it is interesting to note that the subjacent channel at right shows a direction much similar to what a water flow would have. On the point of connection with the main channel it is even darker and possesses one clear dark patch much like the one seen before...

    Besides note that the dark patches tend to the center of the channels. Also a good indication for a liquid flow...

    http://ida.wr.usgs.gov/html/m07018/m0701863.html
    The "Wall of Falls". Well first we have to give some credit to the fact that the preview JPG images are "enhanced" probably in ways less scientific. But even looking at them one may note that the black patches are not "games of light and shadow" NASA loves so much to claim. They are real features of the surface. Besides, note that this place possesses clear indications that large quantities of water passed here in the past. Besides note how layered is the terrain.

    In general there are four-five regions of Mars who may claim the large presence of water. Besides, there could be some chances that we see these regions because higher latitudes are too frozen to have such pockets under the surface. But what this means to life? Think, a planet that possessed an ocean and probably several seas. Well water went somewhere due to some large catasthrophe (that's right large one, the canyons in several places show clearly this). However not all water went away. It was kept underground and it is still in liquid form. Life? Well the chances now are not 1 in 100000000 but maybe 1 in 1000 or even 1 in 10...
  • Hah, I found these 2 comments more useful that the darn news article itself. I didn't know that many differences about the sugar. But, if he does use that assymetry as a test... and I think you said it is only partially assymetrical...does that mean that some reaction could still take place? I know you said it would only be a strong indicator...but can you really predict reaction or no-reaction without knowing the molecules on the surface? -Corey
  • yeah, this one is dead on. Its being carried on several newswires including space.com. & nasa (http://www.space.com/scienceastronomy/solarsystem /water_mars_001201.html) Im vaguely curious about it, myself. I suspect it has something to do w/ water errosion or something like that. I would like to see this post moderated up. The fact that nasa does not plan t carry it on their broadcast channel implies that its really not that significant however. They plan to cover some space-walk stuff.
  • Interesting... I was not aware of the conclusions drawn up by Dr. Lovelock. However, I assure you that I came to this hypothesis after some reasoning and logical thinking about life and how it seems to pervade every possible corner of our earth.

    Nathaniel P. Wilkerson
    Domain Names for $13
  • Not really. Why would an organism evolve with an enzyme that fits either stereo isomer of a molecule made by life on earth like a glove? If you find this, you have found an organism that is adapted to metabolising a sugar.

    Stereo-selectivity isn't an inherent property of katalysts (if only!). The stereo selectivity of an enzyme is the result of millions or even billions of years of evolution, fine tuning the enzyme for that one specific task.

    Having organisms that metabolise dextrose (or sinstrose), also implies that you have organisms that produce those molecules. Non biological processes that produce these molecules are rare, and not stereo selective. An organism doesn't evolve an enzyme finely tuned to metabolising an isomer that isn't there.

    My personal opinion is that if there is life to be found on mars, it is of the chemo lithotrophic variety deep below the surface, or perhaps photosynthesising organisms in the polar ice caps. The surface (where the samples were taken) is a very unlikely place. Anything containing water is going to be freeze-dried at those conditions (low temperature and extremely low pressure). If they are there, please please please let them be discovered during my lifetime.

    I agree that it is not completely unthinkable that spores of some earth bacteria could survive whatever violent process ejected them from the earth with a velocity of at least 11 kilometers per second, millions of years in deep space and impact on mars. Some organisms from earth could even survive there, but not on metabolising dextrose.
  • Why is it difficult to imagine that life would evolve to use sugars? They're simple, easy to make, and even found in interstellar molecular clouds (IMCs). I'd be more surprised if they weren't common to life everywhere, regardless of its origin.

    As far as stereo-selectivity goes, there's good evidence that small-scale structure is inherently chiral: look at carbon single-wall nanotubes, or gold nanotubes -- they naturally form stable spiral structures. Almost every nanostructure we make appears to do that. All you need is an imbalance at some point to evolve specificity for one stereoisomer -- and that imbalance can be as simple as the magnetic field from a nearby supernova remnant, biasing the chemistry in an IMC.

    As for life surviving in space, common soil bacteria (Bacillus subtilis) survived unprotected in space [nasa.gov] aboard the Long Duration Exposure Facility (LDEF) for 6 years. That's bacteria, not spores! A recent paper [sciencemag.org] in Science demonstrated that the interior of the martian meteorite recently alleged to contain fossil evidence of life wasn't subjected to temperatures above 40 C during the entire journey from Mars, including atmospheric entry at Earth. And those researchers noted that "every million years, ~10 rocks larger than 100 g are transferred in just 2 to 3 years" from Mars to Earth. It's an energetically-favorable trajectory.

    I'm not suggesting so much that terrestrial life contaminated Mars -- it's much more likely that we're originally martians. A common chemistry won't surprise me at all.

    ---

  • Because for life to evolve that mebaolises sugars, the sugars have to be there in the first place. And in abundance. You can't have garbage pail dwellers without a city and a garbage pail either. It just strikes me as somewhat similar to assuming alien intelligence will probably speak english, because it is such a simple, common language, easy to learn for everyone.

    I can't access that science paper from home, and since it is sunday, I'll just take your word for it that a trajectory of 2 to 3 years is very likely.

    Maybe your opinion is biased by wanting to believe we are all martians, just like mine is biased by wanting to believe life will originate independently just about anywhere, as long as there is carbon, liquid water and an energy source for prolonged periods of time.
  • chiral molecules can exhibit differences in polarity. (a good example is the alpha and beta anomers of glucose - beta is more polar than alpha). given the right solvent system (such as water) they can be separated by crystallization or chromotography. a natural progress could mimic this on mars. So you don't /need/ enzymes to get stereoisomer-specific reactivity.
    which is not to say it wouldn't be interesting anyway - just not defintive :)
  • Try this:

    if you find life the masses are satisfied:
    there is other life on mars(outside earth) if only bacteria, why spend(waste) to go back

    Now nasa has one less marketing tool to justifie it's cost/usefulness. And many personal and group dogmas have to be rethought to accept "other life"

    "to Find life" is a motivation, but to have found life is possibly just a pain in a lot of peoples asses

  • Yeah, the two Anonymous Coward posts above contain links which cause IE to move around annoyingly.

    Only the best and the brightest read Slashdot. Somepeople deserve to die.
  • they take all my tax dollars and give them to some longhair running a screen saver so that they can scan for alien signals

    SETI is privately funded with occaisional grants from the government. Most of your tax dollars are going to giving benefits to the elderly, although this could change now that there is compelling evidence that they cannot cast valid ballots.


  • Re:Such a waste (Score:3)

    by bahtama ( 252146 ) on Friday December 01, 2000 @10:58AM (#587585) Homepage
    We need people like this to be exploring and researching the far-out things. In doing so, they may discover something totally unrealated or solve the problems of the universe. Only time will tell if he was right or wrong. But saying you shouldn't even try, well that's just silly!

    "What Leonardo? A flying machine with blades that spin? You're an obsessed guy who should be concentrating on the problems we have today! Not on some crazy pipe dream!"

    =-=-=-=-=
    "Do you hear the Slashdotters sing,

  • Comment removed based on user account deletion

  • Not as crackpot as it sounds (Score:4)

    by Anonymous Coward on Friday December 01, 2000 @10:59AM (#587587)
    What is interesting about this is that before the probes were sent to Mars, they realized the importance of the experiments for life. So the NASA scientists in charge of experiments made a very explicit protocol to anylize the results of the experiments by -- what exactly would be a positive or negative result, and what to do if the experiments were mixed in the results.

    This was done so that the results could be viewed objectively based on the science and not reinterpreted for the sake of anyone's theroy of whether life was there or not.

    Strangely enough, the results came back and Levin's was positive by every standard established before the mission left earth. The second test was negative. The third test (which was supposed to be a "tiebreaker") was inconclusive.

    The result? NASA changed the standard for Levin's test, declared that it was inconclusive, and that therefore there was no life on Mars.

    It was purely coincidental that many involved in that decision were geologists who felt slighted that their experiments were not flown -- they thought that if there were no life on Mars, they would be able to get all the experiment space on future missions because people would stop sending biological experiments.

    Of course, that was wrong -- we stopped sending ALL experiments because nobody cares on a gut level about geology, we care about life.

    But the greatest crime is that they lied about the results -- it was 100% POSITIVE for life based on the criterea set before the missions were launched.

    But NASA really doesn't like us to talk about this stuff -- that we found good, strong evidence of some biological activity taking place and walked away.

  • More on the new experiment (Score:4)

    by snookums ( 48954 ) on Friday December 01, 2000 @11:00AM (#587588)

    I'm going to go out on a limb here and take a guess at the nature of the new experiment being proposed.

    If you read the description of Gil Levin's other work, you will see that he is the man responsible for discovering a magic indigestible sugar (tagatose). This sugar is indigestible because it is the mirror image of normal sugar (or certain interesting parts of it are). The enzymes that digest sugar are asymmetric and won't fit together with the tagatose properly. This asymmetry is a fundamental property of life.

    If the agent in the soil which produces the carbon-dioxide reacts with one nutrient, but not it's mirror-image, then the agent must be asymmetric. There is no known natrual, non-biological process on Earth that can produce an asymmetric molecule.

    If this experiment provides a positive result, it will not prove the existence of life, but it is a very strong indicator. Even if there is no life, the discovery of a naturally-occuring, non-biological process for producing these molecules will have a huge impact on the pharmaceutical industry.


  • first they take all my tax dollars and give them to some longhair running a screen saver so that they can scan for alien signals
    I think SETI@Home [berkeley.edu] is a privately funded group. Now your government might be pumping money into one or more of the corporate sponsors found on the main page, but that is completely up to the corporates.
    ---
  • Because for life to evolve that mebaolises sugars, the sugars have to be there in the first place.

    Huh... so for life to use free oxygen, it had to be there in abundance first? ;)

    I think life modifies its environment and then adapts to the modifications, so much that we can no longer easily tell what the original environment was.

    Maybe your opinion is biased by wanting to believe we are all martians, just like mine is biased by wanting to believe life will originate independently just about anywhere, as long as there is carbon, liquid water and an energy source for prolonged periods of time.

    Actually, I think you and I agree far more than we disagree -- I just think that life got its start before it got "trapped" on planetary surfaces... like in the interstellar molecular clouds and in protoplanetary bodies. I also suspect it stirs the pot after that, by transferring between the planetary surfaces often enough to keep things interesting, especially within a planetary system.

    I don't doubt that we'll find some pretty bizarre independently-derived life elsewhere (assuming we manage to get there -- or at least send sensors); it's just that the solar system is a very small place, and I think the life here has managed to move around a lot in the billions of years it has had.

    ---

  • Why must life on a completely different ball of dirt conform to our narrow rules of existance?

  • there are most definitely physicochemical non-biological processes that produce assymetric molecules

    Well yes, there are. Many processes have been designed, and are in use industrially, that produce optically pure products from achrial reagents using various catalysts. These processes are very valuable, particularly to the pharmaceutical and polymer industries. However, I know of none of these processes or catalysts occur naturally -- they have all been designed by lengthy research and are usually very costly.


    If a naturally-occuring process on Mars produces optically pure chemicals with activity against biologically important molecules like sugars, then it would be a breakthrough for chemistry, even if it turns out to be a disappointment for the exobiologists.



  • NASA has an article about a project to restore the data from the Viking experiments and make them 'machine-readable' Here [nasa.gov].
  • I might also add that SN1 (nucleophilic substitution) reactions don't really form a true racemic mixture, but that instead optical activity can be observed, mainly because of the ion pair hypothesis.

    What this says is that the dissocation of the substrate yields two ions still loosely associated, and that thus the carbocation, though now planar, is still effectively shielded from nucleophilic attack on the leaving side by the departing anion.

    I don't know, but this might suggest that the R or the S configuration for some molecule was simply present in greater concentration, and that this is why life chose that configuration.

  • There is life on Mars, and I've got proof (Score:4)

    by Flounder ( 42112 ) on Friday December 01, 2000 @10:39AM (#587595)
    They spoke in front of the Supreme Court today.
  • exactly

    Interesting to point out that the sugar substitute he found was discovered while working on the mars mission
  • I think they wrote that into the docs as a feature, though.

    I seem to remember them tauting the "Flightless Birdless" test tube as quite the accomplishment.

  • Another interesting Viking mission note (Score:5)

    by ethereal ( 13958 ) on Friday December 01, 2000 @10:42AM (#587598) Journal

    According to Carl Sagan's Cosmos, when the three tests that were sent to Mars were also tested in Antarctica (a much more hospitable environment than Mars), one of the tests that indicated there was no life on Mars, also indicated there was no life in Antarctica! Coupled with Levin's positive results, the prospects for native life on Mars may be much better than expected.

  • I'm sure Dr. Derek Smark, PhD., would disagree.

    J

  • If I read correctly, it seems the experiment they're referring to in the article was done in 1976. The remainder is about the same guy trying to get more of his life-on-Mars experiments on NASA missions and encountering trouble. Ah, the beauty of government organizations. Anyway, seems like he might be able to get in on a 2005 mission.

    Though I think the idea of life on Mars is a little strange and that most of the scientific experiments "showing" that there's life on Mars are jumping to conclusions just a bit, it doesn't seem like the resources this experiment would consume comes close to justifying denying an interesting experiment.

  • To continue this completely offtopic discussion...

    5:32pm, December 1, 2000
    Incoming message from ICQ user 100000000

    "Come visit my homepage where me and my girlfriends get it on for you to see!
    http://www.goat*&$uckingICQnumber100000000st ealing Hos.com"

  • Lawyers in Space (Score:5)

    by powerlord ( 28156 ) on Friday December 01, 2000 @11:02AM (#587602) Journal
    They need to do a recount! By hand this time and not a mechanical probe hand either! :)

    It is very obvious that we should have lawyers on Mars so for this sort of thing... Who needs scientists when lawyers can make decisons for us!

    I agree 100% which is why I call for the next Mars probe to be outfitted with a Lawyer Landing System (LLS). This is very similar to the system used to successfully allow the Mars Prospector to land, except replacing the airbag with lawyers. Since Lawyers are 99% hot air, and a naturally produced product of California and New York, we should be able to condense them into a small enough space by placing them into sensory deprevation tanks. Once they near the point of deployment, a micro-cassette of the closing arguments in the Gore vs. Bush campaign can be played, there-by causing the lawyers to emit hot air and inflate, protecting the payload from harm during the inevitable rough landing. Those lawyers that survive the landing will then be on hand to arrange themselves to properly argue the case of whether or not there is life on Mars (while those of us back on Earth will be assured that even if there is life, there is certainly no intelligent life).
  • The problem with finding any sign of life off of this festering and fragile is also its attraction.

    This world will terminate and long before the sun turns into a red giant, swallows the earth in its orbit and turns it into slag on the swollen surface of a dying star.

    We'll already have degenerated into an unstable orbit or had the moon continue to assume an eliptical and unstable orbit and smash into us or been crushed under ice or lava or died of plague or... You get the idea.

    A single planet is like a single CPU architecture and a single OS. Vulnerable fragile and ultimately doomed.

    Might as well hack off your testicles and carve out your ovaries because you're just condemming your progeny to oblivion.

    And where's the sense in that.
  • Well, if those martians give us any trouble, we could all ways break out the Slim Whitman records. Shock troops armed with the sounds of the yodeling cowboy. Yeah!
  • My favorite part of the article is the part where they said his experiment isn't worthy because his credentials were not good. Like a good idea has never come from some non-educated person, and this guy had a degree from John Hopkins. Imagine something like this in our industry where a vast majority of the people don't even have a bachelors degree.

  • Re:A fictional author isn't a good center (Score:3)

    by ethereal ( 13958 ) on Friday December 01, 2000 @11:10AM (#587606) Journal

    Not sure if this is a troll or not, but:

    • Carl Sagan was not a fictional persona, and generally did not write works of fiction. Cosmos was not a work of fiction.
    • Mars hasn't really been scanned very much - we've sent a few fairly stupid robots which have explored less territory than the state of Rhode Island. Sure, there's the Mars Global Surveyor, but although that covers a lot of territory, it's not exactly a close inspection of the places where life forms would hide - underground, or just under the surface of large rocks are likely spots. We're not going to see bacteria (or anything up to the size of a small mammal) from a satellite.
  • Try this [nasa.gov].

    I wonder what Jim Garvin is doing on this panel. His main work is with MOLA (Mars Orbiter Laser Altimeter); this instrument is making nice topo maps of Mars. Perhaps his laser zapped and killed a Martian. Yup, that would be news worthy.

    Factoids: Jim has a ScB from Brown and a MS from Stanford, both degrees in computer science! He then moved on to work in Planetary Sciences where he earned his PhD at Brown. Jim is an ex(?) hockey goalie and has the mentality of one. Jim claims to have crashed an IBM mainframe computer by putzing with variables in an APL program.

  • Lets face it, its a dead planet. I hate to be pessimistic but if there were really life on Mars and it had been around for a few million or so years don't you think evolution may have taken place and these life forms evolved to some degree at least to be a bit more detectable by our measurements. We have about as much chance of find life on Mars as we do on the Moon I figure.

    We may find extinct lifeforms or signs of previous living creatures to be more exact but the likelihood of find "living creatures" is very small I would think. Take a look at pictures of earth from space and compare them to Mars. Our planet is a living planet, swarming with life, every inch of our planet is covered with some form of life whether it be whales, bacteria or spores from a fungus. If Mars had any life at all don't you think that life would propagate around the planet filling every possible nick and cranny that is habitable just like earth? I guess what I'm trying to say is that if there were life then it would be easily detectable by us.

    Nathaniel P. Wilkerson
    Domain Names for $13
  • Look for MARS: The Living Planet by Barry E. Digregorio with Dr. Gilbert Levin and Dr. Patricia Ann Straat. Published by Frog, Ltd.

    This book is informative but needlessly shrill. I personally don't think Digregorio did Levin any favors writing this book. However, if you skip the paranoid ravings about biological warfare and contamination threats there are a couple of good points scattered through the books.

    Read the book and find out.

  • Mr. Gates was rewarded with detailed knowledge of alien computer technology gleaned from a crashed UFO

    Oh, so that's the origin of the term "crash".
  • Actually, this is highly ironic...

    In the early days, NACA (the predecessor to NASA) was mostly made od can-do types, rather than academics. However, when NASA really got in the public eye (and got glamorous), there was a big push to get their people graduate degrees --any graduate degrees.

    A friend of mine's father was big in the space suit design effort, but had little formal education. He told us the 'degree' NASA helped him get was basically a diploma-mill deal with lots of 'life experience' credit. He never put it on his resume, and (perhaps because of being forced to get it) was fond of saying "not bad for a guy who never finished high school" whenever he did something well.
  • Like the rest of the europeans?

  • Testing for life... (Score:2)

    by Anonymous Coward
    I do find it interesting that the experiment assumes life would always metabolize in a way that excretes CO2... But it does seem worth trying again...

    It'd be nice to incorporate a microscope of some kind, but of course the optics would be too pricey and heavy to lug on a cheap probe mission. Maybe we *will* have to wait for human life to get there, and then we can debate whether or not anything found got trudged up with our explorers...
  • The alchohol has killed off the intelligent aliens.
  • On another note, it doesn't make sense why this article doesn't go into greater detail about the test that wasn't consistent with the possibility of life on Mars.

    While I agree with you that I want more information, it was a Washington Post article that's aimed at the masses. They may have had the info to put in there, but most of the uninformed masses don't really care why, they just want to know the results.

  • Links to full text papers (Score:3)

    by Aetrix ( 258562 ) on Friday December 01, 2000 @11:14AM (#587616) Homepage
    The article mentioned biospherics. There website has the full-text reprints of Levin's articles. Here's some URLs:

  • The site is down cause of a hard drive crash
    That's just what they want you to believe.
    --
  • In the late '80s and early '90s The NY chapter of L-5 / Space Studies Institude / Space Frontier Society held meetings aboard the Intrepid Aircraft carrier / museum. (the chapter was founded by Rick Tumlinson of Mircorp)

    Gil gave a talk on the findings of the Viking landers. He was very careful to *NOT* say there was life on Mars, but to just present the evidence.
    His main points were:
    - his experiment was positive for life both on Mars and with Antartic lichen
    - another experiment was not positive on Mars, nor Antartica
    - The final sciences reviews of the data was cancelled due to budget cuts. There is still unexamined data from Viking
    - Stereoscopic pictures of the ground in front of Viking show brown rocks during the winter, and the same rocks as *GREENISH* and *ONE MM HIGHER* during the summer (I wonder if we can download them from NASA's website....)

    I might have an audio tape of this if anyone is intrested.

    After the talk we went out to dinner. What intrigued the women in the group more than life on Mars was that he was working on manufacturing left-handed sugar, which can't be absorbed by our right-handed body chemistry.
  • I hate it when they do this, but NASA is announcing some new discovery on mars dec.7 I wish they'd just spit out the info now. http://www.cnn.com/2000/TECH/space/12/01/mars.surp rise/
  • Well I fell for it, DOH! It does the same thing w/nutscrape in linux as it does in winblows.

  • The experiment (the way the article describes it) was bogus anyway. There is no conceivable reason why martian life, if it exists, would be able to live on burning organic nutrients. Simply because there would be nothing for them to eat on mars, and no oxygen to burn it with.
    If there is life at all (I don't believe it, but I don't exclude the possibility. If it is there, it is extremely unlikely to be in the freeze-dried and irradiated surface layer, where the soil samples were taken from), it will be of the CO2 reducing variety (i.e. taking water and CO2 gas, and making organic molecules from that).
  • Levin's method is pretty ingeneous: determine whether anything is 'breathing' by giving it radio-active carbon dioxide to exhale.

    Don't you think it's kinda cruel? I mean, the first thing we do on another planet is try to poison some of its life forms to see if they are actually present.


    ---
  • Here's some pages from Google on the subject ...

    http://members.aol.com/pgrsel2/phobos12.htm
    http://www.skiesare.demon.co.uk/phob.htm

    There's a bunch more sites that discuss it, the final image taken by Phobos2 was never released by the Soviets for some reason.

    Again, it is rather weird that we have such a high failure rate for probes sent that way, maybe it's nothing but equipment failures but I know that if the Shuttle missions had a 75% failure rate we wouldn't still be doing those :)

  • Re:Life on Mars (Score:3)

    by rve ( 4436 ) on Friday December 01, 2000 @04:17PM (#587625)
    If you did find cells capable of burning dextrose and not sinstrose on mars, you had positive proof of having found earth bacteria.

    How likely would it be that an organism that originated and evolved on mars would use a molecule that is the product of living organisms that originated and evolved on earth as a substrate,
    • and
    use oxygen to burn this molecule (which on earth is the product of organisms that originated and evolved on earth, and is very rare in the martian atmosphere),
    • and
    evolved the same preference for a certain stereo isomer? Organisms like that would be extremely ill-adapted to conditions on mars, yet very adapted to life on earth.

    If you found organisms like that on mars, you have found proof that bacteria from earth contaminated your experiment.
  • Your on the right track with this idea of sugar symmetry.

    I know from my experience in homebrewing ale and wine, we use both right-handed and left-handed sugars for the process. The yeasts (single cell prokeryotes similar to to the "life" we might find on Mars) are able to process the right handed sugars (iirc) but not the left handed sugars. The right handed sugars are added for yeast food, and the left handed sugars are added for sweetening.

    Maybe this tagatose that Levin discovered is just a left-handed sugar, similar to the manufactured left-hand sugar used for sweetening in homebrewing?
  • I have been following this issue since I was in grade school (when Voyager first landed) and even then, it seemed to me that the results were at worst equivocal (NASA itself admitted this at the time). Indeed, my subsequent education (which includes degrees in molecular biology and medicine) has actually strengthened my belief that the original results are not only consistent with , but almost expected of, a microbial lifeform that has spent many (hundreds of?) millions of years adapting to the dissicated conditions of modern day Mars (whatever environment it may have originally evolved in)... the falloff after the initial metabolic response is *quite* unsurprising -- excess water is toxic (via osmotic disruption, interference with local molecular conditions and ionic balances, etc.) even in earth biota.

    Over the years, I collected a NASA data folder for Life on Mars (one of those geek mini-hobbies we all have), but with the advent of the Web, I learned that people found a short reasoned essay with links to actual data and statements on NASA website much more compelling (easy to comprehend, evaluate, and hence accept) than printouts, etc. Unfortunately, that data seemed to move around over the years, and around the time of pathfinder, all the *detailed* informative descriptions of the Voyager results were shoved off all the NASA websites, presumably as old news.

    Does anyone have current NASA links to (detailed) results from Voyager? I prefer to think that those pages were simply relocated or temporarily in Web limbo, rather than 'forcibly retired' as known embarrassments to the agency.

    P.S. At one time, I had a link to an account by a scientist observing the telemetry data as it first came in, apparently he exclaimed "My God, we found life! How do we announce that?" (or words to that effect). He said he was then taken aside and firmly told that he was *not* too express such a viewpoint in the future. I'm sure that many /.'ers know this story, and can provide me with a name, if not an active link to that account (which I did not get from a NASA site, and may no longer exist)

  • Life on Mars (Score:5)

    by deesqrd ( 259920 ) on Friday December 01, 2000 @11:25AM (#587628)
    The Washington Post left out a key element of Levin's experiment and why he wants to do it again. The Viking landers used dextrose, the stuff we and most other lifeforms consume, as bait for possible Mars beasties. He wants to rerun it with dextrose in one chamber and sinstrose in the other. If one and not the other is consumed it's a strong indicator of life since the chemistry of life (as we know it) prefers organics with a specific orientation. If both are consumed, then it indicates weird chemistry, probably inorganic.
  • Let's do some quick calculations.

    Assuming that a mission costs roughly $50 million, and that there are approximately 300 million US tax payers.

    Per capita, each mission consumes $50/300 ~= 17c of your tax money.

    Assuming a snow blower costs about $100 (I'm converting from local currency here and not accounting for price differences), NASA would have to give you your money for 600 missions to buy your snow blower.

    Also, get off your lazy ass and shovel the snow yourself if your wife can't do it quickly enough.

  • Re:No support? (Score:3)

    by Anonymous Coward on Friday December 01, 2000 @11:30AM (#587630)
    ok, he apparently has no supporters other than himself. Peer review seems to say that he is wrong

    No, he has supporters throughout the astrobiology and mars programs at NASA -- just not among the administrators and other factions. There really is no science that says he's wrong, he's just written off as being a nut because his experiments all tested positive and NASA changed the criteria AFTER the results were recieved.

    I suppose that might be plausible, if NASA scientists were a bunch of religionists

    you don't work in research, I'm guessing -- we fight all the time, over funding, pet theories, etc. There are different cliques and fiefdoms all over NASA, each fighting for shrinking budgets and small payload space. There is a several year wait for flight experiments even once accepted -- many scientists would kill their mother to remove another experiment in favor of their own (because their funding might very well dry up before it ever flies!).
  • MAJOR MARS DISCOVERY TO BE ANNOUNCED AT DEC. 7 SCIENCE BRIEFING

    Imaging scientists Dr. Michael Malin and Dr. Ken Edgett from
    NASA's Mars Global Surveyor spacecraft will present what they
    describe as their most significant discovery yet at a Space
    Science Update at 2:00 p.m. EST on Thursday, Dec. 7. Their
    findings are being published in the December 8 issue of Science
    Magazine.

    This science update will be held in the James E. Webb Auditorium
    at NASA Headquarters, 300 E St., S.W., Washington, DC, and will be
    carried live on Telstar 5, transponder 11. The Ku-band satellite
    is located 97 degrees West longitude with a downlink frequency of
    11929 MHz, vertical polarity.

    Please note that, due to coverage of the ongoing Shuttle mission,
    NASA Television does not expect to carry this briefing, and two-
    way question-and-answer capability from agency centers will not be
    available.

    Participants will be:
    * Dr. Ed Weiler, Associate Administrator for Space Science, NASA
    Headquarters, Washington, DC., will be panel moderator.
    * Dr. Michael Malin principal investigator, Mars Orbiter Camera on
    NASA's Mars Global Surveyor spacecraft at Malin Space Science
    Systems (MSSS), San Diego, CA.
    * Dr. Ken Edgett, staff scientist at MSSS.
    * Dr. Jim Garvin, Mars Exploration Program Scientist at NASA
    Headquarters.
    * Dr. Ken Nealson, director of the Center for Life Detection at
    NASA's Jet Propulsion Laboratory, Pasadena, CA.

    - end -
  • "i mean, we can send a canoe from the edge of florida to the keys, why not across the atlantic, c'mon people"
  • That was mentioned in the article.
  • This is great news...
    Now we just need to clone Arnold Schwarzenegger and send the clone to mars to unlock the secret alien oxygen generator. Soon, Mars will be a utopia...

    Wait. Maybe I'm looking in the wrong place for science news.
  • Flame bait or a troll, one way or another.

    No one would deny that a fetus is living material. What all legal arguments have been over is whether or not it is a human being. Different issues, that have no bearing or relevance in a discussion of the possible existence microbes on Mars.

  • Re:Given the last few missions to Mars... (Score:1)

    by Anonymous Coward
    What weird images?
  • Don't be ridiculous. Not only have you failed to cite sources for your ideas, but you believe that there was some kind of conspiracy behind this. NASA would have wanted nothing better than to find conclusive proof of life on Mars. Do you even realise that the mission of the Viking landers was to find life?

    The decision that there was no conclusive evidence of life was the correct and brave decision NASA should have made. It would have been only too easy for them to label inconclusive results as positive.

    I have the National Geographic: Mars book in front of me now, written between the chief scientific correspondent of AP News and the Mars Pathfinder Project Scientist. I quote:

    "There was no money left for testing [of the biological experiments on Viking]... they would have no time to learn how to use them. Some earlier testing had been conducted, but it had been mostly disastrous."

    In addition, none of the experiments were positive for life - two of them could be invalidated due to the fact that, unexpectedly, hydrogen peroxide had been found on the surface (basically screwing up the results and mimicing the behaviour of bacteria). They never expected to find hydrogen peroxide and they never tested for it. No wonder they changed the standards for the tests - it would be criminal to do otherwise. The last experiment, the GCMS (Gas Chromatograph Mass Spectrometer), which was supposed to detect the presence of organic chemicals, found none whatsoever.

    Am I biased against space exploration and life on Mars? Certainly not - I'm the chair of youth outreach for the Mars Society. However, I know how to draw a line between being blindly optimistic and following the scientific method of accepting the most plausible and supported answer.

    Want to know more about the experiments carried on board Viking? Visit here [genmars.com].

  • There is no known natrual,[sic] non-biological process on Earth that can produce an asymmetric molecule.

    Erm... sorry to disappoint you dude, but chiral (a.k.a. asymmetric) molecules are produced all the time, on Earth and pretty much everywhere else, by non-biological processes. Almost anything can be chiral - hydrocarbons, mineral salts, crystals, what-have-you. It would be very cool if chirality were a litmus test for biological processes, but it is most definitely not.

  • Fetuses are life, but not human life. They are merely raw materials for health-drink manufacturers. Yum!

    --
  • ahem... yeasts are single-celled eukaryotes, in that they do have nuclei, intracellular compartmentalization and all the other trappings. So they wouldn't necessarily be the best models for hypothetical life on Mars.
    But that's very interesting about the dextro- and laevo- sugars used in fermentation.

  • NASA needs to send another one of Gil's missions.
    Their current policy is to not allow any manned missions to Mars until we are sure whether or not there is any life there, lest we contaminate the planet before we know. So until we carry out more of these simple tests (so small they could piggyback on a geology mission) we will never know whether or not there is life, and therefore, never land a man on Mars.
    Of course, then NASA will probably come up with some new excuse for not sending men to Mars, like they don't know what kind of life it is or the dang things keep crashing.
  • Why?

    Hey, I spent my youth reading Heinlein novels too. But thinking human space travel is a cool idea is different from having good reasons to do it.

    You don't offer any reasoning to back up your statements. Why do you consider human space travel more important to our species' survival than dealing with greenhouse emissions, the ozone layer, and nuclear weapons?

    --

  • It seems odd that it has already been established that for some reason, a reaction occurs with the testing methods he has set forth. Yet, NASA won't follow up on that, nor his revised test?

    Seems to me life or not he found /something/ that caused that recation there, and that perhaps it is a matter of thinking that all life in the universe has to be life as we know it and understand it. He may have found something else nearly as important, but unfortunately we may not know for a long time if ever. Is it really any mystery that we have not been contacted by any other life out there when we base not only our evolution on silly pieces of metal, but our actions towards our fellow human beings as well. I mean what kind of scientist looks over the data from a reaction like that and says, "eh scrap it" because the other tests failed. What kind of scientist does not want to find out /WHY/ it happened? Our knowledge of our planet and the great expanses beyond it are pathetic, and until we get off our high horses and stop fussing over a damn chunk of metal(Gold) we might find ourselves stuck in Science Fiction and not moving forward much at all if at all.

    He is more a scientist than all of NASA together as he questions and searches for answers in the name of knowledge, rather than in the name of himself and his bank account.

  • PhD (Score:3)

    by Frijoles ( 16015 ) on Friday December 01, 2000 @11:41AM (#587648)
    From the article:

    Eventually NASA accepted Levin's idea for a biology test. But before he could participate, NASA officials told him, he had to get better credentials. He lacked a PhD.

    Apparently at NASA, being smart means having a piece of paper. Either that or they are concerned about some sort of image they wish to portray. I understand that people without those credentials have a harder time, but their ideas should not be discounted because of their schooling.

    • Why can I not see past the horizon?
    • Why do two objects of different weights fall at the same rate?
    • What causes the lodestone to point North?

    The very nature of science is to probe into the inexplicable, to us it would seem a waste of time to try to figure out if there is life on Mars or develop a new kind power source based on nothing more than theory. However, most of mans greatest discoveries are based on or related to the crazy few who devote their lives to false causes. Would I been able to communicate this response to you if someone hadn't wasted their lives on trying to figure out the details of magnetics (which, in turn, lead to the development of electricity and computers)?

    Science by its very nature is absurd to the average person, but it takes someone with vision to make the future happen.

    Capt. Ron

  • Re:Not as crackpot as it sounds (Score:3)

    by Rocketboy ( 32971 ) on Friday December 01, 2000 @12:47PM (#587652)
    Acting under the orders of the Trilateral Commission, a young student, William Gates, was induced to modify computer programming at a major NASA research facility in the mid 1970's. The software modification inserted bogus indications of the presence of hydrogen peroxide in Martian soil samples analyzed by Viking experiments with the express purpose of providing a plausable alternative to other experiments' positive indications of Martian microbial life.

    The Commission desired that the terrestrial public (in particular, the voting population of the United States) believe that no life existed on Mars in order that the American National Aeronautics and Space Administration (NASA) would be financially strangled of public funding and thus not possess the exploration resources it would have received had the general population known of the existance of life on Mars. Had NASA pursued an aggressive Martian exploration program in the mid- to late 1980's it would almost certainly have discovered the secret Trilateral Commission base located inside the caldera of Olympus Mons, which at that time was responsible for the exploitation of the indigenous Martian population in its notorious gold mines. Gold mined from copious Martian resources has been secretly exported back to Earth for the past two decades and the Commission now has all of that valuable metal that it needs for its nefarious plan to destabilize world currency markets, bring on global economic chaos, and eventually end up owning the entire planet outright, which it intends to sell to Vogon civil engineers.

    For the record, as payment for his programming exploit, Mr. Gates was rewarded with detailed knowledge of alien computer technology gleaned from a crashed UFO (see: "Area 51"). Mr. Gate's reward was not, however, as generous as it seemed as the technology he was given was used to create the famous "Windows" line of products which by themselves, due to their instability and unreliability, threaten to demolish industry and bring on global economic chaos.
  • From your remarks, I doubt you've seen scientific peer review firsthand. The real world of science is very different from the idealized, impartial one presented in textbooks.

    The goal of peer review is generally (1) to place a fuzzy lower threshold on what's worth publishing in a journal, and (2) to give the author some feedback and ideas for improving the work before publishing it. From my experience, peer review generally does a pretty good job at both things. A lot of correct but utterly inconsequential stuff gets through.

    A third goal of peer review is (3) to decide what is truly the best science, so that it can be highlighted in the most prestigious journals. I think it does OK at this, but not great. (I had some of my own work that I thought was not the best published in the "better" journals, and had a harder time getting what I considered my own best work into the "worse" ones.)

    What peer reviewing doesn't aim to do is to make revolutions in science or to reinterpret a scientist's data for him. If there had been peer reviewing in Galileo's time, it would have been run by his blood enemies the Jesuits, who were the main scientific authority group. His books would never have seen the light of day. And if someone thinks a scientist's interpretation of his own data is wrong, the usual thing to do is to write a paper in reply, and possibly attempt to reproduce the experiment as well.

    --

  • when there are other, more immediate problems right here that need to be dealt with?

    This is a fallacy. You're simply imposing your own value system on someone else.

    What is it about so many scientists that drives them to absurd interests

    Again, Levin's interest is absurd according to you and others like you. Luckily, not everyone thinks the same way.

    Life on Mars is just like cold fusion - a great idea that will never be proven.

    What is your basis for saying that? It's certainly feasible that a series of well-controlled experiments could settle the issue quite soundly. It sounds to me as though you're saying "we shouldn't try to do things that are difficult."

  • NASA should seriously consider putting this test in. It seems that they really wouldn't have anything to lose. Provided of course that they make sure that the lander won't crash in because the wrong unit of measurement was used. Or that it won't get stuck on a rock. Maybe, for this one they should build an exact replica of the lander used in 1976. Exact in every respect. It worked.

    Eric Gearman
    --

  • Chad in Space (Score:4)

    by powerlord ( 28156 ) on Friday December 01, 2000 @10:46AM (#587660) Journal
    This is a very interesting article in the Washington Post today about an experiment on the Viking mission to Mars apparently found life on Mars - or not."

    Apparently there are a number of uncounted results that have yet to be tabulated. The machine outputted the data from Viking onto punchcards, and the debate is about the status of those cards that were not entirely punched (ie. contained "hanging chad"). "I wish they would either decide that Mars contains life or not" one pedestrian comentated, "I just want to get back to my normal life and this question has been hanging over our heads for far too long already!"


  • Re:More on the new experiment (Score:3)

    by The_Laughing_God ( 253693 ) on Friday December 01, 2000 @11:52AM (#587668)
    Okay, let's simplify this before we debunk it.

    I've seen people do ASCII carbon stick figures of sugars on /. -- but I'm not that ambitious, so do a search. Basically, you can think of a sugar as being a chain of carbons with a H sticking off one side of each carbon and a OH sticking off the other (HOH = water, hence "carbohydrates")

    Take the carbon chain and bend it into a ring (you may have one carbon sticking out, and voila! you have a sugar. The different sugars differ *only* in

    a) the number of carbons (typically 3-7, but longer would also count)
    b) the exact way the end carbons are bound (this is where the stick figure helps)
    c) if the OH's are above or below the ring (as biochemists like to say - up-down-up is different then down-up-down or up-up-up)
    d) some common sugars (like sucrose = table sugar= alpha-glucosido-beta-D-fructofuranoside) are actually multiple simple sugars tacked together. In the case of table suger, it's a glucose ("blood sugar" aka dextrose) molecule bound to a fructose ("fruit sugar")

    That may demystify the 'assymetry' we're talking about.

    Secondly, there are most definitely physicochemical non-biological processes that produce assymetric molecules. Your argument goes way back , but it's pretty old and faded today. Indeed, they are widely used in industry, especially the pharmaceutical industry (to make only one 'handedness', which are more effective with fewer side effects) While originally biological byproducts were used to create that handedness, today we can do it from scratch.

    How could nature produce such compounds? Here's a simple scenario: many chiral compunds prefer to form crystals with their "own kind" (i.e. a recemic mixture carefullt crystalized, will produce D (right handed) and L (left handed) crystals. So somewhere, some time, primeval goo could slowly have crystalized into D and L crystals in some drying puddle.

    Once you have a naturally made D or L crystal, the rest of molecular evolution to 'organic biology' can proceed as we expect. Perhaps there is an advantage to D or L, or maybe it's just that an organism that belongs to the (accidental) majority simply finds more appropriately-oriented "food" or "prey" that it can more easily process. It doesn't really matter which -- though there are some interesting arguments that there are advantages to the overall biosphere to settle on (for example) L-amino acids and D-sugars rather than a random mix of both.
  • Because objects do not define the person, their idea, nor their ability to think and reason.

    Pigs have badges, and if they do the academy right they really get into their power-trip. Would have been interesting to see that sort of logic applied like this back in the riot days of LA.

    PhDs can be bought in this world just like anything, and because somebody has enough money to get one earned or bought does not make instantly superior to anybody else.

  • Are they sure it wasn't just some fungus spores that went along on the probe that are now surviving on the red planet?

    BTW, I think it would be very cool to innoculate Mars with some hearty bacteria/fungus from earth and let it evolve - imho.

    Now I'll go read the article....
  • Well, except that I'm not sure anyone could get
    to the moon anymore. We'd have to recreate the
    technology from scratch, sadly enough.

  • How do you think the Europeans discovered North
    America?

  • Sample return (Score:3)

    by bcrowell ( 177657 ) on Friday December 01, 2000 @01:07PM (#587675) Homepage
    Hollywood to the contrary, sending humans to Mars and bringing them back (!) would be an incredibly difficult feat. I wouldn't count on it in the next century. There are serious health problems involved (long-term zero-g, radiation, and psychological effects) which are not likely to be solved any time soon. The amount of mass involved and the sizes of the delta-vees is just incredible.

    Moreover, there isn't any good reason to do it. Sending humans into space has never yielded any scientific results that were proportionate to the costs. The Apollo program was purely a cold-war porkbarrel project. Don't get me wrong, those guys were my boyhood heroes, but the program was not justifiable scientifically.

    The right thing to do is a sample return mission. A hundred grams of dirt back in a lab on earth would answer the whole question definitively, and it could probably be done within 20 years with moderate funding.

    --

  • When you do your PhD properly you really get inside your subject.

    A PhD is a union card to tenure. It does not indicate that the holder is wise or learned. Quite often is it awarded for bean-counting by young, humorless fools who are being supervised by old, humorless fools.

  • Re:Life is not like cold fusion. (Score:3)

    by notsoanonymouscoward ( 102492 ) on Friday December 01, 2000 @01:22PM (#587679) Journal
    "hack of your testicles and carve out your ovaries"

    I don't know about you my friend, but the vast majority of the population typically has a set of one or the other... or are you one a them unisex Martians?!

    ;)

  • life on mars!! not!! (Score:3)

    by gbd ( 242931 ) on Friday December 01, 2000 @10:48AM (#587681)
    hi all (george here)

    god nasa really piss me off sometimes. first they take all my tax dollars and give them to some longhair running a screen saver so that they can scan for alien signals. now they are looking for life on mars, well maybe they got confused!! see james cameron wrote titanic, that was a movie about a big boat that crashed and it was based on a true story. now this red planet movie is out and apparently nasa thinks THAT ONE is true too, well if they don't know the difference between a foot and a meter that is not surprising, what a bunch of dopes.

    well i've got an idea nasa!! instead of giving my money to the martians how about giving it back to me!! now we are in the middle of WINTER, i (george) would like a snowblower because it takes my wife too goddam long to shovel the driveway in the morning, if she had a machine to do it i could get to work alot earlier. so here is the deal nasa, give me the money, i'll buy a snow blower and then i will be more productive at work and then microsoft will make more money and then paul allen will be able to buy another radio telescope and also the seattle super sonics.

    now do you got that!!

  • Pretty ingenious - not definitive (Score:3)

    by eXtro ( 258933 ) on Friday December 01, 2000 @10:48AM (#587682) Homepage
    Levin's method is pretty ingeneous: determine whether anything is 'breathing' by giving it radio-active carbon dioxide to exhale.

    NASA's answer, while possibly worded too strictly, was correct though. Levin's test gives circumstantial evidence that would support the possibility of life. There are other mechanisms (such as those provided by NASA) which can be used to explain it. All by itself this experiment can't be used as proof of life on mars.

    It would take a number of different tests, enough tests so that explaining the results without invoking the saying "it's alive" would require an impossibly narrow set of conditions to reproduce the results otherwise.

  • (He) created an environmentally safe fly pesticide and invented a sugar substitute that enable diabetics to eat all the sweets they want

    "Every time he opens his mouth about Mars, he makes a fool of himself,"

    It is sad when a person such as Gil Levin devotes so much energy on something that can only meet failure. Obviously he's a bright guy, capable of doing things that have a meaningful impact on society. Yet, he has obsessed for a 1/4 century on something that is at best a pipe dream.

    What is it about so many scientists that drives them to absurd interests when there are other, more immediate problems right here that need to be dealt with? Life on Mars is just like cold fusion - a great idea that will never be proven.

    It's almost like many of these brilliant scientist are in fact just idiot savants. They do one or two great things, then devolve into utter silliness. Tesla set the example in more ways than one, I think...

  • Re:Another interesting Viking mission note (Score:5)

    by SEWilco ( 27983 ) on Friday December 01, 2000 @10:51AM (#587685) Journal
    "...indicated there was no life in Antarctica!"

    Because the penguin did not fit in the test tube. A minor engineering problem.

  • In a second part of Levin's experiment, the soil sample was baked. Any organisms would presumably be killed. The nutrients were reapplied. This time, no gas emerged. To Levin, it meant that whatever had produced the gas in the soil before the heating was now dead.

    So we invade another planet, force feed its habitants and then burn them alive. At least its consistent with US foreign policy.

  • Is there life or isn't life in Mars?
    I think there is. Because there is water. Lots of water... And by some reason NASA doesn't wanna speak about it.

    Wanna see some examples that water is still flowing in mars?:
    http://ida.wr.usgs.gov/html/m00016/m0001654.html
    http://ida.wr.usgs.gov/html/m01000/m0100005.html
    http://ida.wr.usgs.gov/html/m01002/m0100228.html

    Not convinced? Well, some of the most scandalous:

    http://ida.wr.usgs.gov/html/m04018/m0401877.html
    http://ida.wr.usgs.gov/html/m04492/m0449202.html
    http://ida.wr.usgs.gov/html/m08059/m0805951.html

    Not convinced yet? Here it goes. Probably the most fantastic of all:
    http://ida.wr.usgs.gov/html/m08061/m0806185.html

    And this is not over... If you take as many years as me on looking at the hellish surface then you start wondering why some dark stuff loves to be in some places and not in others. And you really start to wonder if this stuff is nothing more than dark spots, sands or rocks. As one example:
    http://ida.wr.usgs.gov/html/m02018/m0201821.html

    Take a VERY CAREFUL look at the picture. If you look well, then you'll see something interesting on these white dunes and sands. They are always spread OPPOSITE to the direction of the winds. They hide behind dunes, hills, heights. And when they seem to be in open field their for loks as if wind blowed OPPOSITE. However the tons of white dunes and the erosion of the place show that the wind is not blowing that way.

    A question. Is NASA telling us everything about that planet? My ideas about dark dunes may still be considered hypotetical. But this does not concerns water. Water is there and only an idiot will not see it. Specially if he has some knowledge on geology. And if water is so abundant as it seems then there is a big chance that life is still there. I mean that. Still there.

    PS: NASA has blown yesterday some news about a major discovery. It will announce it on Thursday. Maybe this? It will be very interesting to know... Time is in syncho with us. The announcement came just a day after some interesting news here.

    Sleep well humans...

  • Well on my previous post I forgot to state also a very interesting frame. It costs gold...

    http://ida.wr.usgs.gov/html/m08076/m0807686.html

    These things are not Hoagland's dreams. These are real things that careful analysis shows that they are no more than monthes or years old. But not millions or milliards as NASA claims. Some of them are "alive" now. I mean in chemical terms. The darkness of these spots shows that chemical reactions are acting now in that place. That's why they are dark. They absorb light to achieve a state o equilibrium. The question still is that whether they are only physico-chemical reactions or is life also acting on the play. But that's another question. What we have now is that Mars still possesses water. Not everywhere and in every place. The most important place is Arabia Terra. Funny? Yes the name of a Earth desertic region is the Martian Amazonia. Besides on the equator... So it seems that Nature is too ironic here...
  • If you found organisms like that on mars, you have found proof that bacteria from earth contaminated your experiment.

    Or: you'd have found evidence that life on Mars resembled life on Earth in some salient characteristics. There are several possible reasons for this, the first two of which are:

    There has been transfer of life between the two plannets in the past, or transfer of life from the same source to each planet. For example, we now know that there are plenty of rocks making their way from Mars to Earth, as has been discussed (by me, among others) numerous times on /.

    This sort of chirality may be inherent in any chemistry complex enough for life to develop in. We simply don't understand either chemistry or life well enough to make a decision on that at this point.

    Furthermore, the fact that an organism uses dextrose doesn't mean it uses atmospheric oxygen to oxidize it. Do a search on "anerobic."

    And finally, your argument also breaks down because the purported martian life might prefer the sinstrose to the dextrose; given the chiral characteristics of terrestrial life, it wouldn't be surprising to find life from an unrelated origin being similarly chiral, but if the particular choice made were accidental, martian life might have a "taste" for the other handedness.

    ---

  • I tend to agree with you, very much; however, there's a NASA-associated culture which wants to argue strongly against Viking results' being positive for life. They initially advanced the "hydrogen peroxide" argument (despite the problems with there being that much hydrogen available without water, and the issues with stability of the compound under martian surface conditions) and then later extended it to a generalized "superoxide" analog.

    Gil Levin isn't the only one who is persistent, however, because a few months back a NASA-associated group published a paper [sciencemag.org] in Science dealing with this very topic. Quoting from the abstract:

    Using electron paramagnetic resonance spectroscopy, we show that superoxide radical ions (O2-) form directly on Mars-analog mineral surfaces exposed to ultraviolet radiation under a simulated martian atmosphere. These oxygen radicals can explain the reactive nature of the soil and the apparent absence of organic material at the martian surface.

    It took them almost 25 years to get this far; does this answer those people who claim that Levin is a flake because he won't let go of his ideas?

    Personally, I think the surface of Mars isn't the place to look for life; I think we need to look subsurface, because of things just like this latest paper. Which, by the way, really doesn't invalidate Levin's tests, because the soil samples included both surface and subsurface material -- added complexity, isn't it?

    ---

  • "They thought Galileo was wrong the first time, too," Levin said.

    ok, he apparently has no supporters other than himself. Peer review seems to say that he is wrong. And he is comparing himself to Galileo.

    I suppose that might be plausible, if NASA scientists were a bunch of religionists. They aren't though. Science seems to have combatted science, and one side fell.

    So we should believe him... why?



  • So this is how we treat life? (Score:3)

    by BradleyUffner ( 103496 ) on Friday December 01, 2000 @10:52AM (#587700) Homepage
    The articale states that the sail was "baked" after the first test to kill off anything that may have bene producing the gas. So we went up there looking for life, and then tried to kill it... No wonder the aliens don't want to talk to us :)

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