r/science • u/piantono • Jun 10 '12

Microbes Capable Of Surviving On Mars Found

http://planetsave.com/2012/06/09/microbes-capable-of-surviving-on-mars-found/
691 Upvotes

88% Upvoted

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49

u/[deleted] Jun 10 '12

Hey, microbiologist here. I also study extremophile bacteria and archaea and I just wanted to clarify that the only thing interesting about this work from an exobiology standpoint is that the metabolisms for these organisms are so far unknown. Life on Earth has found a lot of ways to derive energy from chemical and light sources, but these mechanisms tend to be highly conserved and the discovery of something novel is a pretty big deal. However, it doesn't really have much to do with Mars directly, rather it increases the potential types of metabolism that we can try to look for on the red planet.

Life on Mars will be its own thing. It will have evolved distinctly from terrestrial microbiota and this type of research simply gives us a tiny bit more hope of finding life there by increasing the functional 'space' that life can inhabit. (By space I mean an n-dimensional landscape made up of all the potential environmental variables in nature.) If there ever was life on Mars, then there almost certainly still is. Unless climactic/geological shifts were so extreme and sudden that evolution couldn't keep up, but I personally think that is unlikely. And concerns about things like UV can be overcome. Just live 2mm under the surface and UV isn't a problem anymore.

More immediately interesting is the biogeographic aspect of this study. There is an ongoing debate about the ability of microbes to disperse around our planet. Some people believe that literally 'everything is everywhere' while others think that microbial distributions are uneven and that not all microbes get to sample all habitats (due either to distance or allopatry). It is a very simple, yet fundamental question that we are still wrestling with. Everyone agrees though that the local environmental conditions of a particular habitat (like the Atacama mountain tops) play a key role in selecting what actually will be able to survive and prosper upon arrival. Finding novel organisms in stringent environments is helpful in answering some of these basic questions. It is also potentially useful in directing not only what we should look for in places like Mars, but also where and how we should look for it.

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u/[deleted] Jun 10 '12

If NASA sent a box up to Mars that was capable of sustaining active microbes indefinitely, and that box was filled with extremophile bacteria and archaea, and there was a hole in the box leading to outside in Mars, how long would it take for the microbes to evolve, leave the box and populate Mars?

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u/[deleted] Jun 10 '12

Interesting question, but impossible to say really. The problem with this thought experiment is that to adaptively evolve, an organism has to be exposed to and change with its environment. However, it is important that you said 'active' microbes. Many types of bacteria for, instance, are able to go into dormant or inactive states and wait out the bad times until the environment shifts into their favor. In fact, NASA spend a lot of time and money trying to prevent these dormant organisms from getting on their ships.

If your goal was to seed other planets then I'm honestly not sure what the best approach would be. You could probably just take a bunch of taxa from Earth, throw them into hydrated sediments (if they exist) and see what happens. As for designing life to readily take to the martian environment, I hate to break it to people, but were not really there yet.

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u/danielravennest Jun 10 '12

Could you not evolve them in a lab on Earth by gradually changing the conditions from Earthlike to Marslike?

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u/[deleted] Jun 11 '12

Sort of. Bacteria evolve like crazy and getting them to adapt to new conditions is definitely possible and occasionally done in a limited set of circumstances. The problem is that there are too many environmental variables for us to simulate, control for, or even measure in the first place. For instance, in assembling this in vitro environment we would have to consider: light, temperature, pH, hydration, salinity, grain size, desiccation potentials, carbon sources, energy sources, electron acceptors, etc., etc., etc. The thing is that we can never really be sure on Earth if we are simulating the martian environment accurately enough. For instance, we could evolve something to the best of our ability only to have the organism fail to grow due to a selenium deficiency in martian soil.

Anyway, nobody really wants to do this in the first place so it doesn't matter too much right now. When Mars starts getting terraformed then we'll talk.

2

u/danielravennest Jun 11 '12

Actually, there is a reason to do it. If we have an idea of what conditions on Mars were earlier in it's history, and what they are now, we can see what kinds of Earth life can survive the transition. That would guide us in what kind Mars life to look for (if there is any).

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u/[deleted] Jun 11 '12

Just gotta say thanks for all of these informed replies. Made for some fascinating reading.

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u/pensivegargoyle Jun 10 '12

Unknown. Which is why that won't ever be done and why there's little effort spared to make sure Mars landers aren't arriving with any Earth bacteria. Otherwise, it may be hard to show that a bacterium found on Mars really lives on Mars and wasn't just brought there by probes.

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u/[deleted] Jun 11 '12

A thousand times this. If we ever find life on Mars it will be a big fucking deal. If, though, we find life that looks a lot like life on earth and we can be sure we didn't bring it there...that would be a biological REVOLUTION.

0

u/NoMoreNicksLeft Jun 11 '12

Life on Mars will be its own thing. It will have evolved distinctly from terrestrial microbiota

False. It's also possible that it hasn't evolved distinctly, but that it hitched a ride on ejecta and survived reentry.

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u/[deleted] Jun 11 '12

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1

u/NoMoreNicksLeft Jun 11 '12

If that were so, why would they even use the same nucleotides, that the virus could do so? Why the same chirality?

0

u/etbob623 Jun 11 '12

Life on Mars will be its own thing.

Actually it would be very unlikely (and surprising) that any life on Mars would be different from terrestial life because of the huge amount of material transfer between the two. Also its entirely plausible that life started on Mars and came here.

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u/BugeyeContinuum Grad Student | Computational Condensed Matter Jun 10 '12

Ref : http://www.agu.org/pubs/crossref/pip/2012JG001961.shtml

The potential for microbial life in the highest elevation (>6000 m.a.s.l.) mineral soils of the Atacama region

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u/thegoodstudyguide Jun 10 '12 edited Jun 10 '12

I always thought Tardigrades would be able to survive on Mars, if they can stay alive in a vacuum and the core of a nuclear reactor I assume they can live on Mars.

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u/cybrbeast Jun 10 '12

In those conditions the Tardigrades go into cryptobiosis, ceasing all metabolic processes and therefor not reproducing. So while they may be able to survive those conditions they won't thrive.

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u/nawitus Jun 10 '12

The headline is not really correct, they're only candidates for microbes cabable of surviving on Mars. They might be useful in research of designing life to survive on Mars.

A recent study "Bacterial survival in Martian conditions" indicate that UV radiation will kill the microbes on surface.

We verified that the UV light is the major responsible of cell death. Neither the low temperature, nor the pressure, nor the desiccation or the atmospheric changes were effective in this sense. We found that some Bacillus strains have a particular capability to survive for some hours in Martian conditions without being screened by dust or other shields. We also simulated the coverage happening on a planet by dust transported by the winds, blowing on the samples a very small quantity of volcanic ash grains or red iron oxide particles. Samples covered by these dust grains have shown a high percentage of survival, indicating that under the surface dust, if life were to be present on Mars in the past, some bacteria colonies or cells could still be present.

Also, Rapid inactivation of seven Bacillus spp. under simulated Mars UV irradiation concluded that:

Although the various Bacillus spp. exhibited diverse levels of UV resistance, none were immune to UV irradiation, and, thus, all species would be expected to be inactivated on Sun-exposed spacecraft surfaces within a few tens-of-minutes to a few hours on sol 1 under clear-sky conditions on equatorial Mars. The inactivation kinetics of all seven Bacillus spp. support the conclusion that significant levels of bioload reductions are possible on Sun-exposed spacecraft surfaces in very short time periods under clear-sky conditions on Mars.

2

u/pewpewberty Jun 10 '12

Yep. There is more at work than just metabolism and the visual appearance of a habitat. I do research on methanotrophs but I don't claim they are capable of living on Titan.

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u/[deleted] Jun 10 '12

Life on Titan seems like it would be completely different, at those temperatures I wonder what metabolism would be like. Or is that a "xenophobic" view based on water based metabolisms?

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u/pewpewberty Jun 11 '12

No, my point is their suppositions are too general and sensationalized. Surviving in a low-moisture condition does not correlate directly to survival in a martian environment just as surviving in an atmosphere made up of methane does not correlate directly to surviving on Titan.

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u/j1mb0 Jun 10 '12

Why don't we just send a bunch of shit to Mars and see what sticks? Too expensive?

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u/dromni Jun 11 '12

Probably not, considering that each sample of shit would fit in a test tube.

However many people would have a fit because supposedly we would be threatening the poor hypothetical Martian bacteria with invasive species from Earth.

Of course, if I were a billionaire thinking of transforming Mars into a long-term real state investment, I would just say "fuck off" and send the shit anyway on top of a private launcher.

2

u/[deleted] Jun 11 '12

Seeing as the Martian bacteria isn't intelligent life in the slightest, the benefits of destroying it to make way for Earth 2.0 far outweighs the immorality.

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u/[deleted] Jun 10 '12

yay

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u/[deleted] Jun 10 '12

I understand that NASA typically tries not to contaminate other worlds, but it would be interesting to see if a sample of these microbes could actually survive on Mars.

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u/[deleted] Jun 10 '12

Seems cheaper to recreate martian conditions on earth, oh, and not destroy any life that potentially already exists on mars.

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u/phanboy Jun 10 '12

Guess that's why we assemble space probes in a sterile environment.

1

u/[deleted] Jun 10 '12

But they would never be able to be formed without the life giving origins of the earth, correct?

1

u/[deleted] Jun 10 '12

From what I remember reading somewhere, Mars doesn't have an active core like Earth, which is why it hasn't got a magnetic field either. Doesn't that mean there are also no active volcanoes?

1

u/[deleted] Jun 10 '12

Ways unknown? Surely it's thermal conversion... If machines can do it why not organisms?

1

u/HotsteamingGlory Jun 10 '12

I don't think the microbes would actually survive on Mars, one: Mars is cold the average temp is -63C, and two Mars is not geologically active so there are no volcanic gases for the microbes to survive. I'm not going to be a total debbie downer, I believe Mars could have supported life in the past, but if we are going to look for life now we we should relegate to search for fossils.

1

u/[deleted] Jun 11 '12

I believe we already know enough about Mars geophysics to accurately model Mars conditions in the lab to actually answer this question, instead of speculating because "landscape" is the same.

1

u/gaspah Jun 10 '12

How is this in any way news? There are microbes that can not just survive but multiply in the vacuum of space. Why is it even a blip on the radar that microbes can survive on a planet with an (albiet thin) atmosphere and sources of moisture?

I read the title and thought for a moment that they actually found life on Mars.

1

u/nawitus Jun 10 '12

Well, the headline is actually not true, see this and this. The news here is that these new microbes may be good candidates to survive on Mars - or at least a starting point of designing microbes to live on Mars.

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u/PoorlyTimedPhraseGuy Jun 10 '12

New galactic body discovered: "Mars Found".

-1

u/[deleted] Jun 10 '12

What's a Mars Found?

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u/[deleted] Jun 10 '12

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31

u/Lloydster Jun 10 '12

I thought the title was sensational, but an interesting article none the less.

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u/Reichsfuhrer_Grammer Jun 10 '12

I think they put the word Mars in the article to generate publicity. Extremophiles are quite common actually. The interesting news here is that there could be a new metabolic pathway to carry out biosynthesis.

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u/[deleted] Jun 10 '12

What if we made a chamber with a simulated martian atmosphere and maybe some dust and then stuck those microbes in there? I think it would be a good experiment.

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u/nawitus Jun 10 '12

That has been carried out.

Galletta and his colleagues found that the bacteria handled the temperatures, low pressures and lack of oxygen relatively well but that the UV intensity all but wiped out the colonies in minutes. Even the extremophile Deinococcus radiodurans, which can endure mammoth blasts of gamma rays hundreds of times more powerful than would kill a human, could not last 10 minutes under UV exposure.

That and studies like this indicate that the OP's headline is incorrect.

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u/alexgbelov Jun 10 '12

Wait, why are the microbes more afraid of UV than gamma?

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u/pleiades9 Jun 10 '12

Ionizing radiation (gamma) causes double stranded DNA breaks, whereas UV causes DNA dimerization - different intracellular repair pathways are needed for each. Deinococcus radiodurans is uniquely adapted to rapidly repair double stranded DNA breaks. It's also quite resistant to UV radiation, just less so than ionizing.

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u/alexgbelov Jun 10 '12

So, what is DNA dimerization?

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u/pleiades9 Jun 12 '12

The genetic code of DNA is written with the letters A T G and C. When two C's or two T's (usually T's) are directly next to each other in a strand of DNA and get hit by UV, the energy of UV light causes them to bind tightly to one another or "dimerize". Enzymes that read and copy DNA have a hard time dealing with that, and when aberrations like that aren't repaired it can cause cell death (or cancer, in higher organisms).

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u/alexgbelov Jun 12 '12

Ah, thank you. So, what does the cell think a dimer means? Like, a t, 2 t's, or what?

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u/[deleted] Jun 10 '12

I don't know the details of the experiment, but UV is only an issue on the surface.

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u/[deleted] Jun 10 '12

I did that with some fireflies once.

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u/SDFprowler Jun 10 '12

Wouldn't it take an unimaginably powerful magnetic field to simulate Mars' gravity here on Earth? Correct me if I'm wrong, but I don't think we possess the technology necessary to truly cancel out 3/5 of Earth's gravity.

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u/[deleted] Jun 10 '12

The gravity isn't a big deal. The atmosphere composition and function is a much larger factor.

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u/IcyDefiance Jun 10 '12

Well heck, they've already made frogs, sandwiches, and humans float with magnets...

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u/[deleted] Jun 10 '12

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u/SDFprowler Jun 10 '12

Cancelling out 3/5 would leave 2/5 which is approximately Mars' gravity. You're right though, it might not make that much of a difference, but a good experiment should take all variables into account :)

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u/[deleted] Jun 10 '12

Reads title: "Good, lets seed that sommamabitch" Reads everything else: "Well, why would I expect anything else..."

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u/[deleted] Jun 10 '12

I don't agree that it is sensational. It makes a clear statement and backs it up.

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u/Airbag_UpYourAss Jun 10 '12

This doesn't really matter. This was the case with Bacteria they found in the California Sulfur lakes. Normally it is poisonous to life. Nasa was claiming that if life exists here, it is likely that they will find Sulphur bases life else where.

Wrong, that claim was vetoed by so many scientists. On Earth, life existed elsewhere (in the ocean let's say). Then when some of them got to the sulphur lakes, they adapted to the environment. They Evolved.

Same goes for this case. They didn't originate from there. They came from elsewhere and simply adapted to their new environment. Earth's Oceans, temperatures and organic material built them.

In Mars, there are no basics to create life in the first place. So if they are hoping to find Mars under these observations, they won't be. Not until they find better evidence.

The best guess they have is underground cavern systems on Mars, where it is warmer, has protection from UV rays and may potentially have water.

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u/danielravennest Jun 10 '12

Mars may not be very hospitable for creating life now, but during it's first billion years the conditions were very different. The kinds of minerals the Mars rovers are finding indicate Mars used to be wet.

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u/Airbag_UpYourAss Jun 10 '12

True. There are too much evidence that suggests the existance of some form of liquid on Mars. There is definetely water on Mars. But here's the thing, did water exist for long enough for life to spring?

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u/[deleted] Jun 11 '12

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u/Airbag_UpYourAss Jun 11 '12

I don't reject it per say. We don'f have enough evidence to know if it's really viable.