Extremophiles On Mars Could Survive For Hundreds of Millions of Years 36
One of Earth's toughest microbes could survive on Mars, lying dormant beneath the surface, for 280 million years, new research has shown. The findings increase the probability that microbial life could still exist on the Red Planet. Space.com reports: Deinococcus radiodurans, nicknamed "Conan the Bacterium," is one of the world's toughest microbes, capable of surviving in radiation strong enough to kill any other known life-form. Experiments have now shown that if Conan the Bacterium or a similar microbe existed on Mars, it could survive 33 feet (10 meters) beneath the surface, frozen and dried out, for 280 million years. In a study led by Michael Daly, who is a professor of pathology at Uniformed Services University of the Health Sciences in Maryland and a member of the National Academies' Committee on Planetary Protection, scientists tested half a dozen microbes and fungi -- all "extremophiles" able to live in environments where other organisms die -- to see how long they could survive in an environment that simulated the mid-latitudes of Mars. During the experiments, organisms faced temperatures as low as minus 80 degrees Fahrenheit (minus 63 degrees Celsius) and exposure to ultraviolet light, gamma rays and high-energy protons mimicking the constant bombardment of Mars by solar ultraviolet light and cosmic radiation sleeting down from space.
After the bacteria and fungi had been exposed to various radiation levels in the experiment, Daly's team measured how much manganese antioxidants had accumulated in the cells of the microbes. Manganese antioxidants form as a result of radiation exposure, and the more that form, the more radiation the microbes can resist. Conan the Bacterium was the clear winner. The researchers found that Conan the Bacterium could absorb as much as 28,000 times more radiation than what a human can survive. This measurement allowed Daly's team to estimate how long the microbe could survive at different depths on Mars. Previous experiments, in which Conan the Bacterium had been suspended in liquid water and subjected to radiation like that found on Mars, had indicated that the microbe could survive below the surface of Mars for 1.2 million years.
However, the new tests, in which the microbe was frozen and dried out to mimic the cold and dry conditions on Mars, suggested that Conan the Bacterium would be able to survive 280 million years on Mars if buried at a depth of 33 feet. This lifespan is reduced to 1.5 million years if buried just 4 inches (10 centimeters) below the surface, and just a few hours on the surface, which is bathed in ultraviolet light. [...] The research also determined why Conan the Bacterium is so resistant to radiation. The scientists found that chromosomes and plasmids, which carry genetic information, in the microbe's cells are linked together, which keeps these structures aligned and prevents irradiated cells from breaking down until they can be repaired. "Although Deinococcus radiodurans buried in the Martian subsurface could not survive dormant for the estimated 2 to 2.5 billion years since flowing water disappeared on Mars, such Martian environments are regularly altered and melted by meteorite impacts," he said in a statement. "We suggest that periodic melting could allow intermittent repopulation and dispersal."
The findings were detailed in the journal Astrobiology.
After the bacteria and fungi had been exposed to various radiation levels in the experiment, Daly's team measured how much manganese antioxidants had accumulated in the cells of the microbes. Manganese antioxidants form as a result of radiation exposure, and the more that form, the more radiation the microbes can resist. Conan the Bacterium was the clear winner. The researchers found that Conan the Bacterium could absorb as much as 28,000 times more radiation than what a human can survive. This measurement allowed Daly's team to estimate how long the microbe could survive at different depths on Mars. Previous experiments, in which Conan the Bacterium had been suspended in liquid water and subjected to radiation like that found on Mars, had indicated that the microbe could survive below the surface of Mars for 1.2 million years.
However, the new tests, in which the microbe was frozen and dried out to mimic the cold and dry conditions on Mars, suggested that Conan the Bacterium would be able to survive 280 million years on Mars if buried at a depth of 33 feet. This lifespan is reduced to 1.5 million years if buried just 4 inches (10 centimeters) below the surface, and just a few hours on the surface, which is bathed in ultraviolet light. [...] The research also determined why Conan the Bacterium is so resistant to radiation. The scientists found that chromosomes and plasmids, which carry genetic information, in the microbe's cells are linked together, which keeps these structures aligned and prevents irradiated cells from breaking down until they can be repaired. "Although Deinococcus radiodurans buried in the Martian subsurface could not survive dormant for the estimated 2 to 2.5 billion years since flowing water disappeared on Mars, such Martian environments are regularly altered and melted by meteorite impacts," he said in a statement. "We suggest that periodic melting could allow intermittent repopulation and dispersal."
The findings were detailed in the journal Astrobiology.
Stopwatch (Score:4, Funny)
Average Person's Reaction (Score:2)
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Mars surface temperature is about -81 degrees F.. So yeah.
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Very funny. In all seriousness, microbial life on Mars would dramatically refine our understanding of where pockets of life can survive, and potentially provide evidence of some type of panspermia. Between that and the recent insight into how red dwarf stars are less likely to host what we think of as habitable planets, we've got better numbers to plug into fun things like the Drake equation.
Obviously we'd still have no idea how many planets with
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....our understanding of the precursors would improve by an order of magnitude at the very least.
And, with better understanding of the precursors, a better bound on L, the mean length of time that civilizations can communicate [wikipedia.org]. This may be relevant to humanity's future.
Another reason not to allow humans on Mars (Score:2)
Re: (Score:3, Interesting)
Re: Another reason not to allow humans on Mars (Score:2)
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And that's one of the reasons why they're now sterilizing missions better.
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Worth noting that the camera was probably contaminated after they picked it up.
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Reading the article, I think that any mars robot on the surface is fully sterilized every few minutes.
Mir proved otherwise.
Full sterilization is astoundingly difficult to achieve.
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Any life hardy enough to live on Mars, even below the surface, is extremely well-adapted to the environment and has enjoyed billions of years of evolutionary pressures. The notion that Earth life, which this study clearly explains is at best capable of shutting down all metabolic processes and hiding, would actually out-compete native Mars life is absurd.
This isn't like an invasive species situation on Earth where the alien organism may love the new environment. We don't have anything that enjoys reproducin
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Any life hardy enough to live on Mars, even below the surface, is extremely well-adapted to the environment and has enjoyed billions of years of evolutionary pressures. The notion that Earth life, which this study clearly explains is at best capable of shutting down all metabolic processes and hiding, would actually out-compete native Mars life is absurd.
This isn't like an invasive species situation on Earth where the alien organism may love the new environment. We don't have anything that enjoys reproducing in Mars conditions, and we couldn't because we don't have any comparable conditions.
But there are some things that need looked at. Assuming we establish a million people on Mars in a few decades, they will almost certainly be living in caves - unless we manage to find a way to take a large city's worth of infrastructure from Earth to Mars. Or we will need to mine raw materials from below the surface to build external structures. That will put us in direct contact with any life that exists below the surface.
The question then becomes - what might this life do to humans?
Already, life on
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A million people on Mars? Will never happen. The place is insanely hostile and almost everything, from electronics to toilet paper, would have to be imported from Earth. Mars never had plate tect and thus few minerals. Humans would have to a live a miserable, lonely life inside caves. You could never have children on Mars since they could never return to Earth. The soil and air, what little there is, are poisonous and very cold. It would be way nicer living in a cave on Earth. At best, you would have a dozen people for a few years until they begged to go home.
Musk's plans fall right apart in the cold light of reality. Watch some of the Common Sense Skeptic's stuff on Youtube. Here's one to start - not about living per se, just the physics of creating methane fuel.
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A million people on Mars? Will never happen. The place is insanely hostile and almost everything, from electronics to toilet paper, would have to be imported from Earth. Mars never had plate tect and thus few minerals. Humans would have to a live a miserable, lonely life inside caves. You could never have children on Mars since they could never return to Earth. The soil and air, what little there is, are poisonous and very cold. It would be way nicer living in a cave on Earth. At best, you would have a dozen people for a few years until they begged to go home.
Musk's plans fall right apart in the cold light of reality. Watch some of the Common Sense Skeptic's stuff on Youtube. Here's one to start - not about living per se, just the physics of creating methane fuel.
Sorry, here's the link https://www.youtube.com/watch?... [youtube.com]
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Humans would have to a live a miserable, lonely life inside caves.
How I learned to stop worrying and love the Martian caves...
Gen. Turgidson: Doctor, you mentioned the ratio of ten women to each man. Now, wouldn't that necessitate the abandonment of the so-called monogamous sexual relationship, I mean, as far as men were concerned?
Dr. Strangelove: Regrettably, yes. But it is, you know, a sacrifice required for the future of the human race. I hasten to add that since each man will be required to do prodigious...service along these lines, the women will have to be selec
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If we are worried about killing foreign life forms on other planets, humans should never leave earth again.
I think settling Mars is idiotic until people are living under the ocean. Its a lot easier to live a few meters under the sea than on Mars.
But, I"m not at all concerned about killing microbes on some foreign rock.
Telepathically drawing humans to Mars (Score:2)
Musk being very susceptible to that. Once there, people will be drawn into a symbiotic relationship with our Extremophile Overlords, and together they'll open wormholes so other solar systems can be explored. I guess that would make people like Trills, and hopefully equally good looking.
Very long shot (Score:2)
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This life on Mars stuff is being way overblown recently.
Yeah, ever since the 70s. I've been hearing about this kind of thing since I was a kid in the early 80s.
Time to move on the the next non-story
The odds are pretty good that they are going to find some form of simple life on Mars. If you don't care that's fine, but it's interesting to biologists.
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How soon... (Score:2)
That's nothing (Score:1)
We have creatures in Congress that have survived for billions of years...and they are the exact same creatures as they were billions of years ago, no reproducing necessary.
Calvin (Score:2)
Can we name them Calvin?
Roundtrip tickets ended (Score:2)
Return trips back to Earth from Mars is No-Go.
Planetary survival can’t risk a Martian level calamity on Earth through inadvertent introduction of a destructive lifeform brought back from Mars. Elon’s punching one-way tickets.
Frozen (Score:2)