If Bacteria Can Survive the Atacama, Maybe They Can Survive Mars

By Charlotte Hu | February 26, 2018 2:59 pm
(Credit: Shutterstock)

(Credit: Shutterstock)

Life finds a way, even in the most inhospitable conditions.

In extreme environments such as that present in the hyper-arid center of the Atacama Desert, there are still signs of life. In the most Mars-like location on Earth, a microbial community survives, showing episodic biological activity in the near absence of any moisture. In dry areas at of the desert’s core, where everything is bombarded by intense ultraviolet radiation, Dr. Dirk Schulze-Makuch and his colleagues detected microbes that were not only active but reproducing.

And, as the thinking goes, if life finds a way here there’s a good chance it can find its way on the Red Planet. The study, published Monday in the journal PNAS explains the significance of life establishing roots in such an unforgiving place.

Theory used to hold that organisms found in the most desolate parts of the Atacama were simply unlucky micro-hitchikers deposited there by the wind. But this latest study shows that, far from dying in the Atacama, many of these microorganisms are forging new generations in a hellish landscape.

“What we’re showing is that there’s actually organisms that live there and reproduce, so the area is actually transiently, at least, habitable,” says Schulze-Makuch.

As researchers approached the epicenter of the Atacama, bacterial populations became sparse. Species that were found in the wetter areas were nowhere to be seen in these driest parts. It’s likely that environmental selection and genome specificity had a role in filtering and shaping the microbial community as the landscape grew more unforgiving.

Many of the organisms dwelling near the surface were had adapted to UV radiation and desiccation. Deeper down, they found bacteria that had adapted to the high salt concentrations present in the soil. It was thought that Archaea—an ancient form of bacteria—were more capable of withstanding extreme conditions and hardship. However, the samples indicated that bacteria mostly populated these areas, which means they are hardier than we’ve given them credit for. The main problem they face is the lack of water, but they can do without it for a considerable amount of time. During high and dry periods, the bacteria go into a dormant state, and only reawakened following access to water via rain or fog.

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“This is of course very relevant if you have an environment that is say, on Mars, where it is a tick more dry,” says Schulze-Makuch. On Mars, there’s also occasionally some moisture, typically from snowfall to fog. “This is a direct analogy of what we have in the Atacama Desert. It makes it, in our view, also more likely you have life on Mars and that life can hang in there.”

Life on Mars?

Given Mars’ wet history, the transformative forces of evolution and logical intuition, it’s not exactly going out on a limb to predict life might find its way on Mars.

“We know very early on, 4 billion years ago, there was much more water on Mars. We know from the curiosity rover there were still lakes 2.8 billion years ago. Early on they had water, so the organisms on Mars, microorganisms, if they exist, they would have adapted slowly to drier and drier conditions,” explains Schulze-Makuch. “So if you have these kind of things that are equipped with what would be sufficient to ensure microbial survival if they are there. We can’t really say that they are there now, but our research suggests that it’s a possibility, then they could still be there.”

In the next couple of weeks, the team is headed back to the Atacama Desert to study how organisms adapted to such a harsh environment. On a separate, but related, grant project supported by the European Research Council, Schulze-Makuch is also testing how samples from the Atacama Desert fare under simulated Martian conditions.

Meanwhile, the durable Atacama Desert bacteria are hanging tight, awaiting the next major rain event. Although they’re not exactly flourishing in the current state of affairs, they can still make a living there, which is all anyone can really ask for.

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  • http://www.mazepath.com/uncleal/EquivPrinFail.pdf Uncle Al

    DO!:10.1029/2009GL037497 might be a bit much even for extremophiles. Anammoxosomes are awesome! Building a whole organism that way seems unlikely given ladderanes plus perchorate is rocket fuel..

  • OWilson

    50 years and billions of dollars spent looking for life on Mars and the answer is no!

    (There is better evidence that there was life on the Moon!) :)

    • Hubbell

      whatever. I have a cold today.

    • Sean Cruz-Salvadores

      Never heard about life possibly existing on the moon in the past. Where did you see that?

      • OWilson

        At least a dozen astronauts were there about 50 years ago! :)

  • Hubbell

    Looks like Arizona, or New Mexico. Who cares, frankly.

    As usual, ” If GOD wanted ” . . . .. life to emerge there, it would.

    It hasn’t and it won’t. The smartest intellectual wastes his time and ours with this stuff.

    • mastema

      OMG CONSPIRACY

    • Karen D

      The same can be said about theologians, and people who believe in God or Gods…….They waste their time and ours with trying to convince us of a non existent form of life

      • Simon Sesame

        Prove it!

      • gene456

        How many extra-terrestrial TV shows has that 56-year old SETI Project come up with?

  • Jim Beam

    There may be life. There may not be life. I think I covered it.

  • Mike Richardson

    The Atacama Desert may be one of the closest analogues to Mars here on Earth, but it’s still practically a rainforest compared to the Martian surface. Extreme dryness, temperatures comparable to Antarctica, air far thinner than even at the top of Mt. Everest, and lethal levels of radiation make Mars very inhospitable to life, at least at the surface. Underground, however, may be a different story. We know places where subsurface water exists, where the temperature is warmer, and where life would have protection from deadly UV and cosmic radiation. The only way to know for sure if there’s actually life beneath the surface, though, will be to go there and do some digging.

  • Vic Ferguson

    What I can not figure out is how NASA can be certain it is not “polluting” the Martian surface with earth life. As I understand it, it is next to impossible to be certain of completely, 100% sterilizing microbes from the many probes that have been sent to Mars. If someone can enlighten me on this I would appreciate it.

    • OWilson

      It’s become a scrap yard, for crashed, dumped, obsolete circa 1970 Radio Shack remote toys!

      As long as they can get grants, they won’t take no for an answer on finding Martians!

      50 years of nothing, but they still insist, “It makes it, in our view, also more likely you have life on Mars and that life can hang in there.” Lol!

      • Vic Ferguson

        So the logical next step is to send people up there so that they can dig around in a much more exquisite fashion than any robot could ever do. Encouraged by Elon Musk, who will take some time out from revolutionizing the auto industry–if Tesla can only survive–people are lining up to volunteer for the first manned mission to Mars. Terms of employment for this mission being that it will be a 1 way trip. From the pictures we have seen of the Martian surface, I, for one, would find living out the rest of my days there as something less than idyllic. I can see the definite possibility that I might become bored with the lifeless landscape, until dying from the radiation sickness that would be likely following the high radiation doses from the trip there.

        • OWilson

          It’s just the old Treckies 80s naive dream to “terraform and populate” Mars.

          Meanwhile 98% of our Goldilocks Blue Marble planet is unpopulated and would offer a comparitively bigger and better bang for the buck!

          The poles, the oceans (with windows, even!)
          and far cheaper access back to the Big City for a weekend break!

          But as long as Musk/Bezos has this dream, let him spend his own money how he choses, and hopefully something of value to society at large will emerge!

          (For a primer on failed terrestrial Bioshere 2, see Wiki!)

  • gene456

    So because they managed to find some microbes in a remote desert, they come to the far-fetched conclusion that there “may be”, “could be”, “quite possibly might be” life on Mars. After years and years and billions upon billions of dollars spent on unmanned missions to Mars, THAT is the best they can come up with? And when you couple that with the SETI Project that after 56 years of scanning millions upon millions of radio frequencies, has not found even a single sliver of evidence to suggest any intelligent civilizations have sent out any prior radio signals, we can more and more come to the conclusion that life does NOT exist outside of Earth. All that empty real estate out there – imagine that?

  • Larry Leffler

    The closest star with possible habitable planets is 4.2 light years away. If there were intelligent life there, and if they could understand our radio frequencies as being intelligent signals, and if we could understand their communications, it would take over years round trip for a radio communication to get back to us after we sent one to them. The farther out we go with our signals, the longer it will take for anyone on Earth to get a return message. In reality, with our present technology, most people sending a signal alive today would not be alive by the time a signal was returned. As for life on Mars, if it exists, it won’t be little green men say “howdy, set a spell.” It would be microbial, and very likely, a microbe that has not been seen on Earth. Since any robots on Mars have not been designed to look for such life yet, it is no wonder we haven’t found it. What has been found is that life could very well have survived in the distant past. All this article is stating that since life can exist in the harshest conditions on Earth, then we can use that information to try to understand where to look on Mars under similar conditions. It’s not a waste of money by any means to explore the stars, especially since humanity will one day need to spread out there in the future if we are to survive as a species.

  • Jaunges Kaune

    It’s with-in the most harmonious agreement that we’re all attempting to understand the Universe or its perplexities of mystery, and reward. While the cosmos has evolved from a creativity of beauty, and mysterious time. A Universe that has expanded from the beginning of wonder, and the etherness of its own mysterious unknown. As the cosmos mysteriously reincarnates in the challenges of its own perplexity, and the affinities of an ever-changing beyond. The perplexity of ethereal mysteries or its etherness of an infinite beauty that stems from the affinities of infinitesimal mysteries or other material beyonds. As the expansion of an uneven beginning that attempts to cast doubt upon the wonder of its own creation and infinitesimal rewards. . .

  • chris9465

    I’ve been seeing this story a lot.

    These stories are trying to imply that there parts of the planet earth that are sterile?

    It doesn’t matter where on this planet you go you will find microbes.

    If I’m wrong someone point me to this place.

  • nik

    600 million years ago, the Earth emerged from a state nicknamed ”Snowball Earth” where the Earth was in deep freeze for around a 100 million years, and totally covered by ice and snow.
    The only life that survived was bacteria and algae.
    All present life on earth is considered to have evolved from those life forms. So to ask the question, ‘can life survive on Mars,’ is puerile.
    What is more pertinent, is that the surface of Mars was probably electric arc eroded, by discharges between it, and a passing planetary body. The resultant ‘weld spatter’ is visible in places all over Mars, in the form of ‘blueberries.’ Also the various creeks and gorges on Mars cannot have been formed by water, in most cases, and were formed by arc erosion.
    The likelihood of any surface bacteria surviving this electric sterilisation is small, to non existent. However, it may be that Mars has had a new inoculation of bacteria, by the various ‘rovers’ that have been sent from Earth.
    There are more ways to colonise a planet, than by sending people. It may take several million years to become ‘civilisation’ as we call it, with all the weaponized murder, but that’s probably all to the good.

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