Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Mars Earth Science

Mars-Like Conditions Sufficient to Sustain Earth-Bound Microbes 78

Posted by timothy from the little-chilly-though dept.
skade88 writes "Does life exist on Mars? We might assume if there ever was life on Mars then it most likely came about when Mars was a wetter and warmer place than it is now. So the question is, if life did exist on Mars in the past, does it still exist? Ars takes a look at how microbes have survived on Earth in environmental conditions much like we currently see on Mars."
This discussion has been archived. No new comments can be posted.

Mars-Like Conditions Sufficient to Sustain Earth-Bound Microbes More

Mars-Like Conditions Sufficient to Sustain Earth-Bound Microbes

Comments Filter:

  • Hmmm (Score:1)

    by Anonymous Coward

    So was it the microbes that were wearing the Mardi Gras beads [slashdot.org]?

  • They're Earth-bound? (Score:5, Funny)

    by plate_o_shrimp ( 948271 ) on Thursday December 27, 2012 @12:17PM (#42404235)

    When are they expect to arrive here?

    • Just watch for zombie mutants. It will have been slightly earlier than that.

    • Re: (Score:3)

      by mcgrew ( 92797 ) *

      Well, woosh me bald...

      Earth-bound as in "microbes that are on Earth and can't leave". In short, microbes from earth could live on Mars. Not bound FOR earth, bound TO earth.

      Hope you get that +5 funny you're going for, but I didn't think the joke was that good.

  • Good and bad (Score:5, Insightful)

    by Hentes ( 2461350 ) on Thursday December 27, 2012 @12:21PM (#42404255)

    On one hand, we have to be even more careful not to contaminate Mars. On the other hand, finding (or creating) bacteria that can survive there could be the first step of terraforming the planet.

    • Re:Good and bad (Score:4, Interesting)

      by Baron von Daren ( 1253850 ) on Thursday December 27, 2012 @02:55PM (#42405419)

      One of the problems with terraforming Mars (and potentially lots of other rocky, goldilocks zone planets) is the lack of a substantial magnetosphere. Earth’s magnetosphere greatly mitigates solar wind and radiation. Solar wind can strip a planet of its atmosphere and solar radiation isn’t good news for ‘earth like’ life.

      The conditions for life might be quite common in the universe, but the conditions for complex Earth like life are much, much more rare (but perhaps still substantial given the numbers). We have a lot going for us here. We are part of a solar system in a ‘quiet’ part of the galaxy. The vast majority of stars in our galaxy, and most others, are in areas of great cosmic violence. They are too close to the galactic core, or too close to a star that goes supernova or hypernova during the evolutionary process. There are planets that don’t have a moon or nearby supergiant plants (like Jupiter, Saturn, etc.) to protect them from comets and asteroids, and they don’t have strong magnetospheres. Of course a planet like Mars does have a lot of these things going for it, it doesn’t have a strong magnetosphere which is a sizable technological hurtle to terraforming (assuming we are terraforming for us).

      Most likely humans will become largely virtual data based organisms long before we develop the technology or focused the resources on things like terraforming planets. If this happens, the need to do things like terraforming other planets kind of goes away.

      • One of the problems with terraforming Mars (and potentially lots of other rocky, goldilocks zone planets) is the lack of a substantial magnetosphere.

        It's okay, I have seen the movie, all we need to do is to get these drill like vehicles, form them up into a train like system, pop a bunch of nukes on board, drill carefully into the core avoiding the city size diamonds, then set of a chain reaction that will resonate through the inside of the planet causing the molten iron to start rotating again and BAM! magnetosphere! Seriously guys, it's not that hard!

        *sips coffee*

      • Re: (Score:2)

        by Jeng ( 926980 )

        Googled "power requirements for an artificial magnetosphere for mars" and came up with nothing useful.

        Most of the threads that I found of people talking about an artificial magnetosphere were talking about making it cover the entire planet, but wouldn't on only have to put basically a large magnetic shield between the Sun and Mars?

      • Re: (Score:3)

        by khallow ( 566160 )

        One of the problems with terraforming Mars (and potentially lots of other rocky, goldilocks zone planets) is the lack of a substantial magnetosphere.

        If you're trying to make a nice environment for people to go from Earth, it's a problem. If you're merely trying to get life to thrive on Mars, then it's not a serious issue.The moderately high radioactive environment of Mars just isn't that big an issue (especially compared to the UV enivornment!). The low gravity of Mars does more to strip Mars of atmosphere than the lack of a magnetosphere.

        Most likely humans will become largely virtual data based organisms long before we develop the technology or focused the resources on things like terraforming planets.

        We already terraformed Earth. Agriculture and urbanization both make huge swathes of Earth more habitable for humans

        • If you're trying to make a nice environment for people to go from Earth, it's a problem. If you're merely trying to get life to thrive on Mars, then it's not a serious issue.The moderately high radioactive environment of Mars just isn't that big an issue (especially compared to the UV enivornment!). The low gravity of Mars does more to strip Mars of atmosphere than the lack of a magnetosphere.

          I alluded to this point when I said “assuming we are terraforming for us.”

          Indeed, Mars’ lower mass/gravitational field strength is a major factor in atmospheric degradation, but Mars has enough mass that it could hold onto an atmosphere should it have a stronger magnetosphere. Of course it could hold on to a more substantial atmosphere with more mass, but the radiation would still be a factor if you wanted Mars to be Earth like. Neither is likely to happen, but I suppose it would be e

          • Re: (Score:2)

            by khallow ( 566160 )

            We have certainly altered the biosphere of Earth, intentionally and unintentionally, but I personally wouldnâ(TM)t count that as terraforming in the most colloquial connotation. I get your point, but itâ(TM)s really usurping my comment to make a separate point.

            An assertion that something is unlikely to happen is weakened significantly, if it has been done successfully and to considerable advantage elsewhere.

            • I’m not sure what your point is exactly.

              I am not denying that the term ‘terraforming’ can have various, graduated connotations. If you wish to argue that farming is a form of terraforming or that human driven climate change is a form of terraforming, I can see the point. That is not the connotation of terraforming I am using though, and that should be clear.

              I think that you may also be arguing that because we have altered Earth’s biosphere it strengthens the case that we can

  • No, the question is: what happened (Score:5, Insightful)

    by Rob Kaper ( 5960 ) on Thursday December 27, 2012 @12:25PM (#42404283) Homepage

    The real question is: if Mars once had Earth-like conditions, is there a risk Earth will end up with Mars-like conditions in the foreseeable future?

    • Yes, eventually the earth will cool down and the seas will sink into the crust and the surface will be dry just like the moon, Mars, Pluto, Mercury and other cold planetoids.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      I don't think anyone is suggesting that because these microbes can suvive in Mars-analogue conditions that Mars is or was "Earth like". Like the authors and some other commenters have pointed out, these experiments covered low temperature, low pressure and low oxygen/high carbon dioxide, but didn't account for things like solar radiation or the chemical makeup of the soil. I'm not saying they're crap, but everyone agrees that they're partial and preliminary.

      Besides, from what little I know of planet forma

    • Earth is much more likely to end up something like Venus than Mars. The Sun is slowly getting hotter, and by about 750 million years from now (give or take a few hundred million years) the temperature on the surface of the Earth will be hot enough that the oceans will be lost into space, and subducted into the Earth's mantle. With no oceans plate tectonics will grind to a halt, which will stop the recycling of carbon dioxide. The combination of large amounts of water vapour and CO2 in the atmosphere will

      • Re: (Score:2, Interesting)

        by Smidge204 ( 605297 )

        The sun isn't getting hotter [skepticalscience.com]. Water vapor isn't light enough to escape Earth's gravity well in any appreciable quantity [sbc.edu]. Plate tectonics are driven by convection currents in the Earth's mantel [wikipedia.org], not the oceans, and if anything the (extremely unlikely) ceasing of tectonic activity would decrease CO2 emissions [columbia.edu].
        =Smidge=

        • Re:No, the question is: what happened (Score:5, Interesting)

          by mrsquid0 ( 1335303 ) on Thursday December 27, 2012 @01:40PM (#42404855) Homepage

          Yes, the Sun is getting hotter as it evolves across the main sequence of the Hertzsprung-Russell diagram. However, this is happening on a time scale of hundreds of millions of years. You are right that it has absolutely no effect on our climate today, but it will over the next 200 million years or so. Water vapour does not escape into space, but it will become a larger part of the atmosphere as the Earth heats up, and water vapour is a very potent greenhouse gas. Eventually the water vapour will be lost. First, as the atmosphere heats up the random motion of water vapour molecules will increase, so more of them will end up in the high-velocity tail of the Maxwell-Boltzmann distribution, and thus have enough speed to escape. Second the changes in the chemistry of the atmosphere will make it easier for water molecules to chemically dissociate (and cosmic rays will contribute too). The net effect is that water vapour will be lost, but on time scales of hundreds of millions of years. Plate tectonics are driven by convection currents in the mantle, but they are lubricated by water. If there are no oceans it is much harder for plates to subduct. Once the oceans are gone plate tectonics become much more difficult. This is thought to be the reason that Venus, a planet with essentially the same mass and internal composition as the Earth) shows no evidence for having plate tectonics. My understanding is that this is still somewhat hypothetical, but that there is an emerging consensus in the the geological community that oceans play a major rôle. Finally, plate tectonics do not drive geological CO2 emission, vulcanism does. While it is true that plate tectonics does cause vulcanism volcanos can happen without it, as we see on Venus, and in Hawaii. So, when plate tectonics stop there will still be CO2 emission from vulcanism. However, the carbonate-sillicate weathering cycle will have stopped, and this is the primary geological way of removing CO2 from the atmosphere. The net effect will be CO2 being added by volcanos, but with nothing to remove it the concentration of CO2 in the atmosphere will increase. Unless if we buy some Puppeteer world-moving technology Earth is in for a hot time around its 5,500,000,000th birthday.

        • Re: (Score:3)

          by Thiez ( 1281866 )

          Your "The sun isn't getting hotter"-article is looking at decades, not millions of years. What the sun has been doing since the 1980s is quite irrelevant to its evolution on larger time-scales. Even your water-vapor article concludes that the oceans could be boiled away if the earth were hotter, in the second to last paragraph.

          Do you even read your own references?

          • Let's give smidge204 the benefit of the doubt here. His first sentence, and first link, suggests that he thought that he was dealing with some nut-job who thinks that global warming is a hoax perpetuated by evil scientists and the organic farming lobby.

            • And also in my defense, the original post was asking "in the foreseeable future" ... 200+ million years is not what any normal person would consider "the foreseeable future." :P

              =Smidge=

    • The real question is: if Mars once had Earth-like conditions, is there a risk Earth will end up with Mars-like conditions in the foreseeable future?

      No. In hundreds of millions of years, yes, it could happen. Now? No, it could not without violating the known laws of physics.

  • [quote]
    Does this mean these organisms can survive on Mars? The authors are appropriately cautious, noting these conditions, while harsh, don't fully capture just how tough the conditions are there. "[These] conditions are only a subset of the total potentially biotoxic physical factors constraining the survival or growth of terrestrial microbes on Mars, such as solar UV, extreme desiccation, solar particle events, and galactic cosmic rays," they write. "In addition, the Martian regolith itself contains nume

    • So far all we have really done is examine the martian surface for signs of life either via satellite or rover. We have yet to try exploring underground in caverns which is probably a ways off. Scientists estimate there is more life beneath the surface of earth living in caves and whatnot than there is on the surface. If life still exists on Mars then its probably not going to be found above ground but somewhere deep underground living in caves and deep beneath the soil.

      • Well, we don't know how harsh the conditions are underground on Mars. We aren't even close to understanding how the life on Earth's surface relates to what is underground. I've never seen any estimates that the biomass of 'deep life' is all that large, but even if it is we can be certain that the energy cycling through that part of the ecosystem is MUCH MUCH smaller than what is available on the surface. Can this deep life survive on its own over geological time? This is certainly an open question. What abo

  • There is as much life in the earths crust as there is on the surface. It is therefore quite possible that there is a lot of life in the crust of Mars.

    • There is as much life in the earths crust as there is on the surface. It is therefore quite possible that there is a lot of life in the crust of Mars.

      How does that logic work, exactly? Assuming that the Earth and Mars are similar enough to compare and that life on the surface is A and in the crust is B. You are saying that on Earth A = B but on Mars that A B, or specifically, since on Mars, to date, A=0, that 0=1. Again, how do you get to that point?

  • It might just be the descendents of a Russian Sneeze: http://www.imdb.com/title/tt1109488/ [imdb.com]

  • Forget accidental contamination. (Score:4, Insightful)

    by runeghost ( 2509522 ) on Thursday December 27, 2012 @12:38PM (#42404361)
    How long before some nation or well-funded group decides that the time to start terraforming Mars is 'right now', and without bothering about world opinion, puts together a tailored package of microbes at just lobs them to Mars?
  • evolved on what we know about mars, since it is largely found on meat. What would be looking for is something that could have evolved on a warm wet mars.

  • >A bit of study showed that they were all relatives of a strain first found growing on refrigerated, vacuum packed meat.

    BLurgh.

  • Go the Titan !

    Why ? Free liquid hydrocarbon compounds. Use a space-ferring Zeppelin and siphon-hose pumps to load the liquid (propane, ethylene or gasoline), then send back to Earth and sell to Exon-Mobil.

    Go to Europa !

    Just more interesting for sciences and astrobiology in particular.

    Wasting so much effort, money and time as ESA and NASA is futile -- a failure pre-made and pre-packaged.

  • We need oxygen-producing bacteria, like cyanobacteria.

    We don't need meat-eating microbes on Mars. Good to see they found out this before-hand. Hmmm... Or did they? How do we know the little rover bugger wasn't filled with them?! Maybe it is already too late!

    • How do we know the little rover bugger wasn't filled with them?! Maybe it is already too late!

      Curiosity's SAM instrument inadvertently contained Florida air in its Tunable Laser Spectrometer, which you might remember caused an early false positive of methane [arstechnica.com] when NASA first tried to sample the Martian air. This Florida air was subsequently evacuated into Mars' atmosphere. But I'm not sure anyone knows what was in that air, and no reporters queried NASA about this contamination.

    • We need oxygen-producing bacteria, like cyanobacteria.

      We don't need meat-eating microbes on Mars. Good to see they found out this before-hand. Hmmm... Or did they? How do we know the little rover bugger wasn't filled with them?! Maybe it is already too late!

      And remember, folks, You Are Made of Meat!

  • Incredibly harsh environment for earth-like life and seemingly nothing to eat, but those are a priori arguments. Not science.

    The Viking labeled release experiment [wikipedia.org]

    may have already found life life on Mars back in 1976. [earthsky.org]
    Maybe.

    Consensus science (taking a vote of scientist opinions) says no, but scientific method says quite possibly yes. I'm usually on the side of the skeptics, but in this case I certainly wouldn't rule out microbial life. It might help if we actually went looking for it again directly as we did

  • Satellites have photographed several fluid bursts from martian cliff walls over the past decades. It is unclear whether the fluid is water or CO2, but H20 is a good candidate. Microbes may have lived below the surface for eons.

    There have been microbes in everywhere they've been looked for in Earth rocks where the temperature is below 120C. Some scientists suggest this may be the largest biomass on Earth due to the huge volume.
  • If we consider life as a tight defined set of molecules interacting in some medium and enclosed in a space we start to realize that life in a water-poor enviorement may not be very easy. Can a different liquid medium be used. Gas? Completly solid? I guess an enclosed space is certainly neccesary and a medium that allows interactions too. There may be life but probably very constrained due to enviromental constraints. For funding, research and peer finding please refer to the non-profit Aging Portfolio.

Slashdot Top Deals

Love may laugh at locksmiths, but he has a profound respect for money bags. -- Sidney Paternoster, "The Folly of the Wise"

Close