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Science

How An Andromeda Strain Might be Strained 136

Posted by Hemos from the pushing-the-limits dept.
An anonymous reader writes "For the world-record holder as the longest surviving bacteria in space [6 years, Bacillus subtillis], it turns out that among the multitude of dangers [cold, vacuum, UV, lack of nutrients, etc.] the greatest stress of all is intense ultraviolet radiation. In the next two years, new space station experiments are slated to test the panspermia hypothesis--also popularized in Robert Zubrin's "Entering Space", but dating back at least 150 years in the scientific literature. Recent balloon experiments, have rekindled alot of the controversy, but NASA Ames scientist, Rocco Mancinelli, concludes: "In my opinion, for a spore, it's quite likely.""
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How An Andromeda Strain Might be Strained More

How An Andromeda Strain Might be Strained

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  • Why is this a surprise? (Score:5, Interesting)

    by slycer9 ( 264565 ) on Monday November 25, 2002 @10:51AM (#4751128) Journal
    It's been a long standing standard that one of the most effective antibacterial/antiviral measures one can take today is UV irradiation, it's one of the few things most movies even get correct. Hell, even most of the studies done about UV irradiation on humans in space is inconclusive. Or has all the hype in the past (Anti-Anthrax measures in post offices) been just optimistic public placating?
    • You just need to make sure you've killed EVERYTHING. Otherwise, if given enough time, the bacteria may develop a resistance through evolution. Apparently there was bacteria on the Mir space station that had evolved (due to the pressures of the environment, etc.) to the point where it could eat through titanium. Of course, this caused all sorts of damage to space station components. The ISS may breed similar kinds of life. Recent measurements have shown that ISS occupants receive the same level of radiation in a day as a human on earth receives in a whole year.

      • Re:Why is this a surprise? (Score:5, Informative)

        by PD ( 9577 ) <slashdotlinux@pdrap.org> on Monday November 25, 2002 @01:44PM (#4752398) Homepage Journal
        This is just SO wrong in so many ways.

        1) There are some things that a bacteria will never be resistant to. Physical attacks against their cell wall, for example.

        2) The bacteria on Mir was not a bacteria. It was a fungus.

        3) The fungus did not evolve. It was a common earth strain.

        4) The fungus did not eat anything. It secreted a corrosive substance.

        5) The fungus did not eat throught titanium. Mir was aluminum.

        6) During periods of high solar activity, astronauts on the space station might get 30 millirems of radiation in a single day. On the other hand, on the surface we pick up 350 millirems from background, and another 150 or so from cosmic radiation in a year. So, ISS occupants do NOT receive the same amount in a day as they would get on the surface in a year.

        • I was citing from memory, so I'm sure the details got messed up somehow.
          5) The fungus did not eat throught titanium. Mir was aluminum.
          Yes, I know that Mir was aluminium. I think they ran tests on the bacteria and found that it could corrode (not eat) titanium.
          6) During periods of high solar activity, astronauts on the space station might get 30 millirems of radiation in a single day. On the other hand, on the surface we pick up 350 millirems from background, and another 150 or so from cosmic radiation in a year. So, ISS occupants do NOT receive the same amount in a day as they would get on the surface in a year.
          What's this [newscientist.com], then? To quote: "Data collected by NASA and a Russian-Austrian collaboration show that astronauts on the ISS are subjected to about 1 millisievert of radiation per day, about the same as someone would get from natural sources on Earth in a whole year."
          • Point #5, OK, I'll give it to you.

            Point #6 - I do not consider New Scientist to be authoritative on anything. Once upon a time, I wrote a letter to New Scientist. They fucked it up. You can read all about it here. [google.com]

            So if New Scientist said it, they're wrong. Utterly wrong. To do a little bit of analysis, a millisievert is 100 millirems. That value of 1 millisievert a day is the same as 100 millirems a day. So in one year, according to the new scientist article, we get 36,500 millirems of radiation at the Earth's surface. When you dig a little bit, you realize that it's probably 100 times too large to be possible. New Scientist is obviously wrong. I bet their lousy illiterate editors changed the text to make it more poetic or some crap like that. They sure don't care for accuracy in reporting.

            This page (too lazy to make a link) http://users.rcn.com/jkimball.ma.ultranet/BiologyP ages/R/Radiation.html describes the dosages in millirems for several things. Among them:

            Normal background, Boston MA: 102 millirems/year
            X-ray technician: 320 millirems/year
            additional dose from living close to three mile island: 8 millirems/year
            Dosage from past nuclear tests: 0.06 millirems/year
            Dosage from Fiestaware pottery: 200 - 300 millirems per HOUR

            If you have some of that old pottery, get rid of it. It's orange, made with a uranium pigment. It's pretty dangerous stuff. The newer stuff isn't radioactive. If you're in doubt, have it checked with a geiger counter.

            • Dosage from Fiestaware pottery: 200 - 300 millirems per HOUR

              If you have some of that old pottery, get rid of it. It's orange, made with a uranium pigment. It's pretty dangerous stuff.

              Or you can keep using it and become a superhero [sentex.net].
    • An interesting (and slightly worrisome) aspect of this is that most radiation, including UV, is known to greatly increase the number and degree of mutations over time.

      Not only does it select for a trait (UV immunity), it causes lots of mutations. Sort of a synergistic Darwinism. Combined with other techniques - What a great way to create nifty new bacteria. Neat, and of course a bit scary.

      • Re:Why is this a surprise? (Score:3, Informative)

        by Cujo ( 19106 )

        OTOH, I have a hard time believing that an organism that optimized its genome for surviving direct exposure to UV radiation would be much good at surviving in our bodies. I don't even know that there is a path through gene space to get there. Only speculation, of course - IANAMB ( I am not a microbiologist).

        It seems an easier strategy would be to hide. You wouldn't need to be very far down inside a meteorite or chunk of space debris to escape UV.

      • While I agree with a couple of the posts above, they're not actually relevant to the story, which, in a nutshell is: 'UV radiation bad to some bacteria'. If they were reporting a modification to the structure of said bacteria, a specific way of mutating said bacteria to be more UV resilient or just a new bacterium more UV resistant than any other, now THAT would be news (ways of modifying humans/others to be less suceptible to the ozone hole for example, etc.) Just reporting that UV + bacteria = dead bacteria doesn't make for news in my opinion.

      • In other words, whatever DOES kill it makes it stronger.... (if it doesn't kill it...)

    • Re:Why is this a surprise? (Score:4, Informative)

      by seschmi ( 531566 ) on Monday November 25, 2002 @01:03PM (#4752067)
      Actually, UV radiation isn't an effective antibacterial measure at all. Unfortunately, UV radiation can easily be shielded - if the germs are hidden behind a barrier (ice, stone) which is thick enough to shield the radiation, they won't care. That's why UV is seldom used for desinfection - if you have germs inside a tool (e.g. an endoscope) or in larger clumps, desinfection will fail. Much better is radioactivity (gamma rays) or gases that are able to permeate plastics (e.g. ethylene oxide).
      • Oh, I'm talking to myself... Anyway, as radiation intensity quickly declines if you depart from the source (to the power of two, if I remember correctly), it shouldn't be an important problem on interstellar journeys, where the bacteria are far away from any source of radiation.

  • Origin of life? (Score:4, Funny)

    by sifi ( 170630 ) on Monday November 25, 2002 @10:53AM (#4751146)
    So we could have all originated from something blown out of an Alien's nose - that sure explains a lot.

  • Lunar Colonists Were Returned To Earth... (Score:5, Interesting)

    by cybrpnk2 ( 579066 ) on Monday November 25, 2002 @10:54AM (#4751150) Homepage
    Another prime example of bacterial space survival was found by Apollo 12 when it brought back parts of the unmanned Surveyor 3 [angelfire.com]. Conrad's quote here has been censored, incidentally; his original quote was a little pithier...
  • Maybe such experiments can show how life may 'evolve' to adapt to the extremes of planets/moons in space.
    • The interesting side effect of this could be the ability to terraform worlds using re-engineered bacteria. Get those suckers breathing in toxic fumes, breathing out the building blocks for human life, and infect millions of worlds.

  • Bacteria on the moon (Score:5, Interesting)

    by jeff_bond ( 135948 ) on Monday November 25, 2002 @10:55AM (#4751170) Homepage
    An interesting link [panspermia.org] about bacteria that was unintentionally left on the moon, and was later brought back to earth alive.

    Jeff

  • Earths bold new defense... (Score:5, Funny)

    by mr_z_beeblebrox ( 591077 ) on Monday November 25, 2002 @11:01AM (#4751196) Journal
    In other news, an invading alien race has left us for health reasons. Apparently we are the descendants of their common cold.

    • Oh! That reminds me! (Score:5, Funny)

      by jabber01 ( 225154 ) on Monday November 25, 2002 @11:50AM (#4751497)
      As I kid, I'd read a story, by Stanislaus Lem IIRC, in which the Earth seeks admission to a Galactic Congress of sorts. After reviewing Earth's pedigree, we are denied memberships on the grounds that the primordial ooze from which we're descended was actually the result of illegal dumping by some aliens. The specifics of the story escape me, but I recall that after purging their septic system on the young and lifeless Earth, the aliens responsible added insult to injury and stirred the pool of waste with a stick, in a clockwise direction, which imparted onto our DNA a right-handed chirality, which is apparently considered mongrel by everyone else in the galaxy.

  • yummm (Score:3, Funny)

    by greechneb ( 574646 ) on Monday November 25, 2002 @11:02AM (#4751204) Journal
    "In the first, she made a sort of layer cake, alternating layers of spores with layers of soil or clay, etc."

    That just ruined my appetite for the day. Anybody want the rest of this layer cake that I'm not gonna eat?

  • seeds are amazing (Score:4, Funny)

    by ch-chuck ( 9622 ) on Monday November 25, 2002 @11:03AM (#4751216) Homepage
    I'm sheltering a strain of politically persecuted plant seeds in my fridg - keep 'em cool, dry and dark. Some have been in there over 10 years and will sprout in a week of warm, damp and dark.

  • Hostile space environment (Score:5, Interesting)

    by panurge ( 573432 ) on Monday November 25, 2002 @11:06AM (#4751227)
    Ever since thiobacter concretivorans was discovered chewing its way through concrete in nuclear reactors, we've known that life is not necessarily restricted to a temperature range of around 0-40C. (That's 32-104F for people who hate the French.) What with the stuff that grows in hot springs at 95C (work out yourselves), and the stuff that lives at the bottom of oceans, we shouldn't really be surprised if microorganisms can survive in space - after all, comets have plenty of ice and dirt, just like the Earth. And no matter how bad the UV, there is going to be somewhere on a comet or small asteroid that is shaded from direct solar radiation. Maybe I'm just being stupid, but to me the argument goes something like (and I may be repeating myself, if so sorry)

    50% of the planets we've actually checked out are inhabited.

    The other 50% have been visited by human beings who have left artefacts behind

    So why do we expect the rest of the universe, including the non-large rocky bits,to be life-free?

    • 0-40C. (That's 32-104F for people who hate the French
      Actually that would be Swedes, since the inventor of the International Standard for temperature was a Swedish scientist named Anders Celsius.
      • Actually that would be Swedes, since the inventor of the International Standard for temperature was a Swedish scientist named Anders Celsius.

        true, but was it not based upon the metric system, invented and standardized by the French?

        (units of 10 or 100 or 1000 - so here, 0 Celcius is freezing point, 100 Celcius is boiling point)

        • It was rather the French using the only scale available that filled two requirements:
          1. Scale that fit the metric idea
          2. Not taken by either Brits or Royal French

          Incidentally, Fahrenheit could be construed as filling the first req. It's based on melt and boil of something other than water, but anyway. It did not fill the second req.
          • If the episode of Connections 3 I just watched tonight is to be believed Fahrenheit developed his scale using a number of weird semi-arbitrary refrences that he actually stole from a lesser known scientist whose notes had burned up (allowing for Fahrenheit to steal the glory, such as it was).

            The scale originally started with the freezing temperature of water beign 0 F and the top of scale being the temperature of a man's healthy armpit (no joke) or approximately 90 F. But there was a need to be cleanly divisible by 8 or some such other nonsense and he started fudgeing the scale with 32 F becoming freezing and 100 F being the healthy armpit. Of course his reading of 100 F was off and human body temp would later be established as 98.6 F.

            http://www.weathernotebook.org/transcripts/2001/ 02 /05.html

      • Kelvin, not Celsius, is the international standard for temperature scales.
    • I've heard this argument quite a bit over the years and while it certainly is true that life can survive in extremely hostile conditions, it does not necessarily stand to reason that life could develop equally well in such conditions.

      Colder conditions are necessarily going to have fewer of the chemical reactions that lead to the bottom of the chain that is life. Hotter conditions are likely to have so much entropy that life either never develops initially or is wiped out over and over again.

      The whole question, however, may be moot. As Zubrin points out in Entering Space [amazon.com], Earth-originating bacteria has possibly already reached other star systems. So as the unmitigated greatness of Red Dwarf [reddwarf.co.uk] posits, it's possible that life evolves nowhere else in the universe than Earth and things are still pretty interesting.

    • Re:Hostile space environment (Score:1, Insightful)

      by Anonymous Coward
      thiobacter concretivorans?
      i would be interested in the publication describing this fascinating creature, as none of the standard microbiological/taxonomical databases seem to know it. if somebody could help me out, please?

  • I'd like to know... (Score:4, Interesting)

    by GeckoFood ( 585211 ) <geckofood@nosPAM.gmail.com> on Monday November 25, 2002 @11:07AM (#4751234) Journal

    ...is how said information would be useful to us, since we already know what stresses bacteria. I mean, are we looking for an advancement in medicine or something, that will, say, extend the shelf life of certain helpful cultures or anything like that? Or is this just for the pure science of it and the satisfation of having knowledge?

    I don't care either way. It's interesting to follow stuff like this, but it makes it a lot more interesting for the spectator when one knows what the goal is...

    • Re:I'd like to know... (Score:5, Interesting)

      by Daniel Dvorkin ( 106857 ) on Monday November 25, 2002 @11:16AM (#4751292) Homepage Journal
      Right now, the goal is just to know. That's it.

      Eventually ... who the hell knows? We may learn something that will have direct medical applications. Or we just have more data to file away in the ever-increasing store of human knowledge, and a century or three from now someone will come along and say, "Hey, I can use this."

      I'm all for applied scientific research (I ought to be, considering I work in biotech.) I'm also all for pure scientific research, since, a) more knowledge is never a bad thing -- yes, I will happily defend that statement against the "things man was not meant to know" crowd -- and b) most of the useful technology we have today was based on what was, at one time, pure science without any obvious application.

      Benjamin Franklin watched the Montgolfier brothers' first balloon go up. When someone else asked him of what use he thought such a thing might be, he replied, "Of what possible use, sir, is a new-born babe?" Exactly.
      • You know, while I've always respected Benjamin Franklin, I think that a hot air balloon is a little big to play 'catch' with.
  • So does this mean that there could be millions of unidentified bacteria in space waiting to infect our planet. Sounds like a bad B movie...

    • Re:Question... (Score:2, Interesting)

      by Andrewkov ( 140579 )
      Seems unlikely to me. Virus and bacteria evolved over millions of years to be compatible with animals and people on our planet. I don't think we'd make good hosts for a parasite that had evolved on another planet. At least I hope not!! ;-)
    • What are you saying? Andromeda Strain was turned into a bad B movie! :)

  • However... (Score:5, Insightful)

    by Skevin ( 16048 ) on Monday November 25, 2002 @11:07AM (#4751239) Journal
    The scary thing about the Andromeda Strain was that it wasn't a bacteria. It wasn't even a virus. It wasn't even organic, moreso a complex molecule that happened to reproduce using heat.

    In other words, some journalist is looking at how long life forms we know and love(?) can survive the harsh conditions of outer space and finding an opportunity to use the term "Andromeda Strain"?

    Solomon
    • Interesting...
      A few people have proposed that all life on Earth is really just a vehicle for a complex molecule (DNA) to reproduce itself. At some point, whether it's at the virus level or at a molecular level, things somehow become living. I'm not sure what the criteria for life is since it seems to vary between different groups of scientists, but it is interesting in that "got nothing better to do on a Monday morning but post on Slashdot" sort of way.

      • Re:However... (Score:2, Funny)

        by SEWilco ( 27983 )
        Humans are just a vehicle for the improved survival of cows. Cows have succeeded in training us to protect and care for them. Their numbers have increased into huge herds on every part of the globe. They are now competing with penguins to get us to take over Antarctica.
        • This is a very interesting theory. Laurie Winn Carlson once wrote about the symbiotic relationship that humans and cattle have shared over the history of mankind. Cattle have also been useful in the prevention of smallpox (remember cowpox anyone?). Little wonder that cataclysmic events in recent history began almost exactly after the rash outbreaks of mad cow disease in Europe.

    • Re:However... (Score:3, Informative)

      by debrain ( 29228 )
      Sounds like a prion [everything2.com], popularly believed to be the cause of mad cow disease et al. Prions are believed to be proteins that self-replicate using host DNA. They gestate over 20 or so years or so.

  • UV Radiation (Score:5, Insightful)

    by Waab ( 620192 ) on Monday November 25, 2002 @11:09AM (#4751249) Homepage

    I wouldn't be the least bit surprised to learn that there are micro-(or even macro-)organisms drifting through space feeding on UV radiation.

    After all, we thought a lack of light would doom the sea floors to lifeless oblivion only to learn that life had adapted to feed on the what was available. Why should we assume that bacteria drifting through the void of space haven't evolved in a similar fashion?

    • Why should we assume that bacteria drifting through the void of space haven't evolved in a similar fashion?

      Probably because in order to evolve, they need to live and reproduce. For this they need liquid water. Without the liquid water there is no "life" in space. Just seeds waiting for the right conditions.

      Bacteria make themselves dormant during hostile conditions. Not to say that an active, living space bug can't exist. It just cant exist with the mechanism that bacteria use.

      • Re:UV Radiation (Score:3, Funny)

        by tftp ( 111690 )
        Without the liquid water there is no "life" in space

        We, beings of Jupiter, do not agree. Liquid water that you are talking about is nothing but insanely hot and barely maintainable substance. Only in our high energy labs such material can briefly exist, and obviously no life can thrive in it either.

        Besides, everyone knows that liquid, pleasantly warm (+20K) methane is most optimal for life. Water that you speak about is just a heresy.

        Signed,
        88736662-99923662 Jr.

    • The reason that bacteria feeding/fueling themselves with UV radiation would be difficult is that UV, as mentioned numerous times here, is really toxic to living things. This toxicity, unlike ones that bacteria manage to adapt to -- heat, pressure, toxins, etc., is a problem for evolution because UV damages DNA in a direct, radiation absorption leading to bond disruption and DNA breakage causing mutation and more often than not, critical mutations that cause organism failure -- death. Using UV as an experimental mutagen is problematic, and not often done for that reason -- it's too good at killing your organism, and not particularly good at leaving you with interesting or functional mutations.

      The bacteria that survive in space probably, and I stress probably because I don't have any personal knowledge of them, survived by hiding. Pigments could theoretically be engineered (and thus evolved) to absorb UV, but given how much of an impetus an organism would need to do this, and how much evolutionary time something like photosynthesis took to get to its fantastic efficiency, it would take longer than a couple decades in space. Could there be bacteria out there that thrive on UV and are in the midst of slowly evolving into plant-like organisms? Sure. Do I think they're out there? Not really -- not if life is generally DNA based. It's just too hard on DNA.

      Kargis Strong, MD

      • Re:UV Radiation (Score:3, Interesting)

        by CowbertPrime ( 206514 )
        Most space 'surviving' organisms do just that. They 'survive'. They lie dormant and shield their DNA using spores or some other sort of mechanism. In any event, they don't have high metabolic rates (that would induce the creation of more oxidants and radicals) and don't divide, as DNA polymerase is very picky about structural morphology and damage such as mismatches or crosslinking will cause polymerase to stall, fall off, or skip the section - it is these times where reproduction of bad DNA becomes fatal. Lysogenic phages also react to UV damaged DNA and excise themselves, enter the lytic cycle and further contributes to cell death.

        However, low dose UV mutagenesis is used quite often, because interesting things happen when bacteria are exposed to UV. Bacteria do have sets of genes that repair UV damaged DNA, in addition to the so-called SOS response. Most UV damage occurs is not directly detrimental - just the formation of pyrimadine dimers which kinks the DNA and either prevents transcription or replication. The uvr (UV Repair) genes along with umu (UV Immutable) genes can do nifty things like replace the beta subunits in polymerase to accomodate structural defects, meanwhile. Prokaryotes even have phr (Photo Repair) systems to fix this stuff using longer wavelength light. Where large sections of DNA are skipped during replication, recombination can be used as a repair mechanism. At least these can keep the cell alive, but incur lots of mutations, which is useful when you are not sure what kind of mutation you are looking for and you don't know the locus so that chemical mutagens are ruled out in addition to site-directed mutagenesis.

  • Simple answer (Score:5, Funny)

    by burgburgburg ( 574866 ) <splisken06NO@SPAMemail.com> on Monday November 25, 2002 @11:09AM (#4751254)
    SPF 5006

    With aloe vera, of course.

    • If bacteria can survive for millions of years in petrolium under ground, I'm sure they can survive for equal time scales in blobs of tar in space. Does this mean that Earth was colinized by life from somewhere else? No, after all that life had to come from someplace and that place might just have been Earth itslelf. It could however, make it possible for Earth to have been colinized and it does make it possible for Earth to continue to receive new life forms.

  • Guess they haven't tested this one (Score:5, Interesting)

    by Anonymous Coward on Monday November 25, 2002 @11:12AM (#4751267)
    "Deinococcus radiodurans is the most radiation-resistant organism known. Deinococcus radiodurans were discovered in 1956 by Arthur W. Anderson at Oregon Agricultural Experiment Station in Corvallis. Among the many characteristics of Deinococcus radiodurans, a few of the most noteworthy include an extreme resistance to genotoxic chemicals, oxidative damage, high levels of ionizing and ultraviolet radiation, and dehydration. "
    - http://deinococcus.allbio.org/
    • On the contrary, D. radiodurans has been tested in space. Here is one of several different experiments mentioned on PubMed:

      FEMS Microbiol Lett 2002 Sep 24;215(1):163-8 "Microbial survival of space vacuum and extreme ultraviolet irradiation: strain isolation and analysis during a rocket flight." R Saffary et al.

      "We have recovered new isolates from hot springs, in Yellowstone National Park and the Kamchatka Peninsula, after gamma-irradiation and exposure to high vacuum (10(-6) Pa) of the water and sediment samples. The resistance to desiccation and ionizing radiation of one of the isolates, Bacillus sp. strain PS3D, was compared to that of the mesophilic bacterium, Deinococcus radiodurans, a species well known for its extraordinary resistance to desiccation and high doses of ionizing radiation. Survival of these two microorganisms was determined in real and simulated space conditions, including exposure to extreme UV radiation (10-100 nm) during a rocket flight. We found that up to 15 days of desiccation alone had little effect on the viability of either bacterium. In contrast, exposure to space vacuum ( approximately 10(-6) Pa) decreased cell survival by two and four orders of magnitude for Bacillus sp. strain PS3D and D. radiodurans, respectively. Simultaneous exposure to space vacuum and extreme UV radiation further decreased the survival of both organisms, compared to unirradiated controls. This is the first report on the isolated effect of extreme UV at 30 nm on cell survival. Extreme UV can only be transmitted through high vacuum, therefore its penetration into the cells may only be superficial, suggesting that in contrast to near UV, membrane proteins rather than DNA were damaged by the radiation."

      If you are interested in bacteria that can live in extremely hostile environments, D. radiodurans is a great example to read up on... it is being bioengineered for bioremediation of radioactive waste.

      An aside for the "radiation causes mutations and hey then there's evolution" crowd, D. radiodurans is believed to have developed its extraordinary radiation-resistance as a side of effect of desiccation resistance. There is no evidence that there is any natural environment that would have led to direct selection of such extreme resistance to radiation. (Although humans have now such created such environments at nuclear reactors or in food irradiation facilities.)

    • Here's a fairly non-technical article if you want to learn more about this bug: ScienceNews [sciencenews.org]

  • I Wish! (Score:2, Interesting)

    by deathcloset ( 626704 )
    what are the chances of a planet like earth with a star like the earths with the chemical makeup of earth getting hit with a comet/big-ass-thing (probably the most likely part of the equation), which is not so terribly big as to wrend the planet into star-orbiting dust, and not too small as to allow the pieces to coalesce back into a nice spheroid, but just big enough to launch a healthy piece (meaning lively) through space to rendevous with a planet like earth with a star.......you get the picture.
    I want just as badly as any other sci-fi buff to make it with a hot alien babe. But let's face it. 2 meter tall, bipeadal, sexy aliens [realm-o-tigger.com] are pretty unlikely...Even more unlikely than life as we know it or most of us getting laid tommorow.
    "We have calculated (in the Mileikowsky paper in Icarus (2000) that in order to protect spores for 1 million years against cosmic radiation, a 1-meter-thick layer of the meteorite is necessary." ...how thick must it be for entry through an atmosphere?
    • You left out the possibility that life arose in the comet fields, and from there was deposited on planets.
    • "We have calculated (in the Mileikowsky paper in Icarus (2000) that in order to protect spores for 1 million years against cosmic radiation, a 1-meter-thick layer of the meteorite is necessary." ...how thick must it be for entry through an atmosphere?

      According to materials I stumbled upon while researching Leonides a few days ago, in order to penetrate the Earth's atmosphere and impact the surface, an object needs to be 50+ meters in diameter.

      So, if a strain of killer bacteria arrives on Earth, we'll surely notice. :-)

  • About Mars and dark sands (Score:5, Interesting)

    by Ektanoor ( 9949 ) on Monday November 25, 2002 @11:32AM (#4751377) Journal
    Well this is not exactly about panspermias but it may be an interesting note about the possibility of life in outter Space.

    I would risk to say that we may already have some evidence (not proof!) that something alive may thrive in Mars surface. Nearly two years ago I got hand in a frame where one could see both light and dark dunes among a rugged Mars landscape. It was interesting to note that dark dunes formed mostly opposite to the general pattern of winblow that could be inferred from light dunes and the erosive processes in mounds and cliffs. Besides, on several places, under certain mounds, one could see how "dark sands" covered one side in a weird manner. They would concentrate over the base of the mound's side and swiftly dissipate the farer they would be from the mound.

    MSS scientist claimed that these pattern was the result of light dunes being "pertified" and that dark dunes being "active". However, in several places, one could be pretty sure that the light mounds were still very active, was they "cut" a dark dune with their edges. Moreover, in one section of this regon, dark dunes would always "hide" behind the bigger and larger light dunes.

    In the whole, it seemed that dark dunes ran away from light and wind, what was quite weird. As the region presented lots of data on how wind acted, the pattern was clear and perfect.

    On other section of Mars I saw an even more weird picture. There, dunes would have clear and well visible "bridges" between themselves - patches that united dunes well far away from each other. In one place, such "bridge" was rising over a mound, going down through a small cliff and uniting two dark dunes quite far apart from each other (maybe more than a few hundreds of meters).

    These strange and weird dark dunes are a mistery in Mars, many of them are clear and pure dunes, only its dark pattern gets quite weird as they don't have a clear origin. However some places show dunes that are only slightly similar to natural dunes. They are more compact, smaller than light dunes, Besides they present a "water drop" pattern rather than presenting the usual crescent shape of most dunes.

    This is not the only weird thing in Mars about "dark lands" There are many more. However this is the most widespread weird feature in the planet. One can see this from pole to pole. However they are not in every place. They are quite localized in certain regions, while others lack them completely.

  • inside rock (Score:3, Informative)

    by peter303 ( 12292 ) on Monday November 25, 2002 @12:26PM (#4751802)
    A few centimeters of rock will sheild against most anything. Microbes have been found as deep as anyone has drilled in the earth- 8 miles, so there are probably lots of microes inside rocks.
  • It kinda hurts the credibility when the top of the rediff.com frontpage says "Channels: Astrology"?
    • I would rethink that. I'm not sure HOW astrology works, but it seems to have a better-than-average way of predicting people's behavior. I always try to get my coworker's birthdays so I can run them past my girlfriend. I would read "Dancing Naked in the Mind Field", besides being a great book (by a nobel-prize winning biochemist) it has an interesting chapter on accuracy of astrology.
  • "That any existing life died out and had to start again, or the "panspermia" theory of life arriving on the meteors themselves." The fact remains that men can still turn the most innocent statements into something sexual. In layman terms "Huhuhhh . . . He said sperm"

  • Don't forget abiogenesis (Score:4, Interesting)

    by job0 ( 134689 ) on Monday November 25, 2002 @12:55PM (#4752007)
    The hypotheses competing with panspermia is abiogenesis. Abiogeneis theorises that life can arise spontaneously from non-life molecules under proper conditions. I tend to favour abiogeneis slightly over panspermia simply because we know
    that there is life on Earth, but we don't know if there is any elsewhere in the Universe.

    The four steps to necessary for Abiogenesis are:

    Inorganic Molecules to Organic Monomers

    Organic Monomers to Organic Polymers

    Formation of membranes from the polymers

    Acquisition of a means of reproduction

    Maybe the asteroids instead of seeding the earth provided the energy required for the first step.

    • However, astronomers have shown that dust particles near UV radiation (e.g. near a star) can form organic monomers from diatomic molecules, such as raw carbon, H2, and O2, because intense UV forms radicals that quickly react with the native species to form such compounds as glycine and acetate.

      Furthermore, the Urey-Miller experiments have been recently underplayed because it has been determined that the early Earth atmosphere did not contain high concentrations of methane and some other compounds that Urey-Miller used as the assumptions for that experiment.

      Abiogenesis seems to be more logically sound than panspermia because as you say, we have no proof of life elsewhere in the universe, so panspermia ultimately still begs the question of 'who was first'. However, abiogenesis has its own issues with inflation (saying that impossible odds can be overcome by postulating an undefined but presumably infinitely large population - if the chance for a reaction involving 2 species is 1E-24, then we postulate that there were more than 2E24 particles in the same volume and that the 2 particular species were close enough to react. It is not merely the inflation of numbers, but inflation of the probability that the two particles are in the same vicinity).

  • What about the moon (Score:1, Insightful)

    by Anonymous Coward

    Surely, if life came to earth in meteors then one would also expect the moon to have had a few impacts from these types of meteors too? My reasoning being its close proximaty to Earth and the shear number of visible craters on its surface. The bacteria may not have flurished on the moon because of the unsuitable conditions but wouldn't wee still expect to find the dormant spores on the moon? If they can survive millions of years of space travel then surely they can also stay dormant on the moon.

    The only argumnet against this is that there was only one meteor which had the spores and it crashed on Earth. But this must be extremely unlikely (that the only life bearing meteor landed on the perfect planet). It must be more plausable to believe that there are a reasonable number of these meteors and some crashed to earth and some to the other planets in our solar system.
  • I had read several of his books in the 80s and my friends thought he must have gone bonkers after being a great astronomer.

    Too bad he passed on before he could be shown to be correct... if this virus from space stuff is proven correct.

    -Ron

  • Simpler Things Harder to Kill (Score:4, Informative)

    by handy_vandal ( 606174 ) on Monday November 25, 2002 @01:26PM (#4752264) Homepage Journal
    Simpler things are sometimes harder to kill. The Andromeda Strain was hard to kill because it was a simple thing which had adapted to an extremely harsh environment.

    Similarly, prions -- the deformed proteins associated with Mad Cow and other transmissible spongiform encephalopathies -- survive autoclaving. Bacteria break down in an autoclave, but not prions, which are much simpler things. Very worrisome, because autoclaving is the standard procedure for sterilizing surgical instruments.

    Contrast this with complex things -- e.g. human beings -- which can be killed in a thousand simple ways.

    More complex, more vulnerable.

    I'm reminded of the "trans-warp drive" from one of the Star Trek movies, I forget which: Scotty shuts down the drive by heisting a few chips, and says with a smile: "The more they tinker with the plumbing, the easier it is to stop up the works."

    • That seems interesting. Because prions are just protein, they ought to denature in an autoclave, just like you would boil a bit of meat.

      And that quote was from ST:III: The Search For Spock where the new Excelsior was sent to stop Kirk after he stole the Enterprise to return to the Genesis planet in order to rescue Spock.
      • I don't know why, but that's the word from researchers -- prions don't denature in an autoclave. There are documented cases where Creutzfeldt-Jacob Disease was transmitted via autoclaved surgical instruments. Consequently, Researchers are EXTREMELY cautious about working with prion-related diseases.

        Very strange proteins indeed: they don't denature under autoclave heat/pressure ... and they cause normal proteins to convert into the abnormal prion form (characterized by spongy holes in brain tissue).

  • spelling (Score:4, Informative)

    by upstateguy ( 90019 ) on Monday November 25, 2002 @01:34PM (#4752339)
    The correct spelling is 'subtilis' A non-pathogenic (except for a few odd-ball cases) gram-positive, sporulating prokaryote. So it acts as a model system for all sorts of nasties including anthrax.

    The B. subtilis spores are *extremely* hardy and were very close (genetically) to the bugs that the one group claimed to have extracted from amber.

    And the japanese eat a fermented soy product made by this guy (natto).

    I worked on that damn bug for my PhD so it's a love/hate relationship. :-)

    • I rather like the use of 'You gram-positive, sporulating prokaryote!" as an epithet. It has much more class than "Yer mother uses Windows!"

  • 6 years? Big deal.... (Score:3, Informative)

    by Kevin Burtch ( 13372 ) on Monday November 25, 2002 @02:42PM (#4752733)
    What about the bacteria found frozen in the polar
    ice caps that "revived" when thawed?
    It was hundreds of thousands (millions?) of years
    old, and still viable!
    I don't remember the specifics... just turn on
    Discovery, TLC, or The Science Channel once in a
    while, you'll stumble over it.

    The popular beliefs of the limits of life are being
    challenged all the time. Just look at the life
    in/near the thermal vents in the deap ocean for
    a comparison in the opposite direction.

    • From the article: Only one in a million spores exposed to space or merely shaded survived ... But spores spared exposure to UV and other light-that is, stored in the dark-fared well, with between 50% and 97% survival

      The frozen bacteria where shielded from UV radiation by hundreds of meters of ice. Which I guess strenghtens the point here, UV kills, and if shielded from it, bacteria can stick around for a long time.
      And that means there's a chance bacteria have been spread between planets by coasting along on a comet or similar.

  • seems dubious (Score:4, Insightful)

    by g4dget ( 579145 ) on Monday November 25, 2002 @04:10PM (#4753424)
    The second evidence was from growths observed from using potato dextrose agar as medium and the microorganism could be identified as staphylococcus pasteuri. Rod-like bacillus and fungus (engyodontium albus de Hoog) were also found.

    I have no problem with the idea that microorganisms can travel through space, if we find evidence for it.

    However, these claims strike me as dubious: these are organisms adapted to earth environments. Staphylococcus pasteuri is grown at body temperature and isolated from human vomit, and Engyodontium album is a eucaryote. Neither of them seems like a good candidate for a space bug, and both of them seem like somthing you would easily get if someone doesn't handle sterile samples carefully. You'd also expect big differences in sequence data.

    If space is full of spores for organisms highly adapted to earth environments, that's a much, much stronger claim than merely claiming that space is full of spores. If they are extraterrestrial, where are these supposed to be coming from?

    The most plausible explanation for these particular results is terrestrial contamination. If they want to prove anything more, the experiment really needs to be repeated many times and under different conditions. And they really should find some differences in the DNA sequences.
    • My thoughts exactly, but you beat me to it. I don't think we need boggle at the idea of terrestrial bacteria in the upper atmosphere. Once they get there by any means (volcano, airplane, an extraordinarily high-powered sneeze) they might remain aloft for years.
  • We are all descendants of septic goo from the Planet Krypton.
  • they're so indestructible but basically made from protein? they survive surgical autoclaving. how to kill them then. can they be inhaled?


  • We have meteorites that we think came from Mars.
    Presumably, there are meteorites from Earth on Mars, Venus, and maybe even Europa.

    If we see no signs of earthlike DNA in those places, then I would say the likelyhood of panspermia goes way down.

    I don't have a problem believing that life evolved from inorganic materials all by itself.
    But then, lots of people believe in weird things.

  • Michael Crichton's "Andromeda Strain" is a great book on this topic.
  • I always remembered Fred Hoyle and N. Chandra Wickramasinghe's book - Diseases from Space, as the first place that I heard about Pan Spermia. Look here [actionbioscience.org] for an article by N.C.W that was posted last year about the supporting evidence. At the time, the whole issue concerning bacilli was that they are the best shape for surviving the passage through the upper atmosphere.

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