With Mars methane mystery unsolved, Curiosity serves scientists a new one: Oxygen

NASA/Goddard Space Flight Center

This is a sunset at the Viking Lander 1 site, 1976.  Credit: NASA/JPL

This is a sunset at the Viking Lander 1 site, 1976. Credit: NASA/JPL

For the first time in the history of space exploration, scientists have measured the seasonal changes in the gases that fill the air directly above the surface of Gale Crater on Mars. As a result, they noticed something baffling: oxygen, the gas many Earth creatures use to breathe, behaves in a way that so far scientists cannot explain through any known chemical processes.

Over the course of three Mars years (or nearly six Earth years) an instrument in the Sample Analysis at Mars (SAM) portable chemistry lab inside the belly of NASA’s Curiosity rover inhaled the air of Gale Crater and analyzed its composition. The results SAM spit out confirmed the makeup of the Martian atmosphere at the surface: 95% by volume of carbon dioxide (CO2), 2.6% molecular nitrogen (N2), 1.9% argon (Ar), 0.16% molecular oxygen (O2), and 0.06% carbon monoxide (CO). They also revealed how the molecules in the Martian air mix and circulate with the changes in air pressure throughout the year. These changes are caused when CO2 gas freezes over the poles in the winter, thereby lowering the air pressure across the planet following redistribution of air to maintain pressure equilibrium. When CO2 evaporates in the spring and summer and mixes across Mars, it raises the air pressure.

Within this environment, scientists found that nitrogen and argon follow a predictable seasonal pattern, waxing and waning in concentration in Gale Crater throughout the year relative to how much CO2 is in the air. They expected oxygen to do the same. But it didn’t. Instead, the amount of the gas in the air rose throughout spring and summer by as much as 30%, and then dropped back to levels predicted by known chemistry in fall. This pattern repeated each spring, though the amount of oxygen added to the atmosphere varied, implying that something was producing it and then taking it away.

“The first time we saw that, it was just mind boggling,” said Sushil Atreya, professor of climate and space sciences at the University of Michigan in Ann Arbor. Atreya is a co-author of a paper on this topic published on November 12 in the Journal of Geophysical Research: Planets.

As soon as scientists discovered the oxygen enigma, Mars experts set to work trying to explain it. They first double- and triple-checked the accuracy of the SAM instrument they used to measure the gases: the Quadrupole Mass Spectrometer. The instrument was fine. They considered the possibility that CO2 or water (H2O) molecules could have released oxygen when they broke apart in the atmosphere, leading to the short-lived rise. But it would take five times more water above Mars to produce the extra oxygen, and CO2 breaks up too slowly to generate it over such a short time. What about the oxygen decrease? Could solar radiation have broken up oxygen molecules into two atoms that blew away into space? No, scientists concluded, since it would take at least 10 years for the oxygen to disappear through this process.

“We’re struggling to explain this,” said Melissa Trainer, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland who led this research. “The fact that the oxygen behavior isn’t perfectly repeatable every season makes us think that it’s not an issue that has to do with atmospheric dynamics. It has to be some chemical source and sink that we can’t yet account for.”

To scientists who study Mars, the oxygen story is curiously similar to that of methane. Methane is constantly in the air inside Gale Crater in such small quantities (0.00000004% on average) that it’s barely discernable even by the most sensitive instruments on Mars. Still, it’s been measured by SAM’s Tunable Laser Spectrometer. The instrument revealed that while methane rises and falls seasonally, it increases in abundance by about 60% in summer months for inexplicable reasons. (In fact, methane also spikes randomly and dramatically. Scientists are trying to figure out why.)

With the new oxygen findings in hand, Trainer’s team is wondering if chemistry similar to what’s driving methane’s natural seasonal variations may also drive oxygen’s. At least occasionally, the two gases appear to fluctuate in tandem.

“We’re beginning to see this tantalizing correlation between methane and oxygen for a good part of the Mars year,” Atreya said. “I think there’s something to it. I just don’t have the answers yet. Nobody does.”

Oxygen and methane can be produced both biologically (from microbes, for instance) and abiotically (from chemistry related to water and rocks). Scientists are considering all options, although they don’t have any convincing evidence of biological activity on Mars. Curiosity doesn’t have instruments that can definitively say whether the source of the methane or oxygen on Mars is biological or geological. Scientists expect that non-biological explanations are more likely and are working diligently to fully understand them.

Trainer’s team considered Martian soil as a source of the extra springtime oxygen. After all, it’s known to be rich in the element, in the form of compounds such as hydrogen peroxide and perchlorates. One experiment on the Viking landers showed decades ago that heat and humidity could release oxygen from Martian soil. But that experiment took place in conditions quite different from the Martian spring environment, and it doesn’t explain the oxygen drop, among other problems. Other possible explanations also don’t quite add up for now. For example, high-energy radiation of the soil could produce extra O2 in the air, but it would take a million years to accumulate enough oxygen in the soil to account for the boost measured in only one spring, the researchers report in their paper.

“We have not been able to come up with one process yet that produces the amount of oxygen we need, but we think it has to be something in the surface soil that changes seasonally because there aren’t enough available oxygen atoms in the atmosphere to create the behavior we see,” said Timothy McConnochie, assistant research scientist at the University of Maryland in College Park and another co-author of the paper.

The only previous spacecraft with instruments capable of measuring the composition of the Martian air near the ground were NASA’s twin Viking landers, which arrived on the planet in 1976. The Viking experiments covered only a few Martian days, though, so they couldn’t reveal seasonal patterns of the different gases. The new SAM measurements are the first to do so. The SAM team will continue to measure atmospheric gases so scientists can gather more detailed data throughout each season. In the meantime, Trainer and her team hope that other Mars experts will work to solve the oxygen mystery.

“This is the first time where we’re seeing this interesting behavior over multiple years. We don’t totally understand it,” Trainer said. “For me, this is an open call to all the smart people out there who are interested in this: See what you can come up with.”

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From EurekAlert!

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86 thoughts on “With Mars methane mystery unsolved, Curiosity serves scientists a new one: Oxygen

  1. “Within this environment, scientists found that nitrogen and argon follow a predictable seasonal pattern, waxing and waning in concentration in Gale Crater throughout the year relative to how much CO2 is in the air. They expected oxygen to do the same. But it didn’t. Instead, the amount of the gas in the air rose throughout spring and summer by as much as 30%, and then dropped back to levels predicted by known chemistry in fall. “

    Any hope this “extra” O2 is biological in origin is unfounded.
    Simply physical chemistry still to be elucidated.

    Seasonal swings due to temperature of the surface in the dominant gas CO2 explains it. The poles are coevered in CO2 ice every winter only to be outgassed as the sun returns. A harsh sun of UV with no ozone to block EUV. And N2 and Ar are one species. So the O2 can come from both H20 and CO2 dis-associating under UV at the north pole a the end of winter. Plus there is a lot of oxygen in the red oxidized soil that can equilibrate to warmer temps.

    Yes, there is much to learn. But we do not need to send astronauts there to die just to return some Mars dirt.

    • A harsh sun of UV with no ozone to block EUV.

      @ Joel O’Bryan ….

      If there is O2 in the Martian atmosphere ….. along with a harsh sun of UV radiation, ….. then why no O3 (ozone)?

      Is atmospheric chemistry on Mars different from that on Earth?

      • Chapman Theory predicts more ozone in the stratosphere than is there.
        In the 70’s two researchers got a Nobel Prize for solving the ozone problem by realizing chlorine aides in ozone destruction.
        https://www.e-education.psu.edu/meteo300/node/595

        Dr Trainer above notes that CO2 or H2O dissociation can’t account for it the O2 rise). But they said nothing about perchlorate, ClO4 . ClO4 is a
        Very abundant in Mars soils and Mars soil dust is very fine and stay airborne on Mars for long periods.
        https://www.researchgate.net/publication/242525435_Perchlorate_on_Mars_A_chemical_hazard_and_a_resource_for_humans

        So that would be both my next guess for an O2 source and the reason O3 there would have a very short half life in Mars very cold, thin atmosphere with Chlorate ion present.

      • As on Earth, ozone is very likely created high in the Martian atmosphere by UV acting on oxygen but due to physical-chemical reactions with other atmospheric constituents, including dust, just never makes it way down (i.e., diffuses or is convected) to near surface-level, which is the atmosphere that the lander is sampling.

        Also, there are is a limit to the concentration of ozone that is detectable by the SAM instrument. It may be at the hundreds-of-ppm level, whereas ppb level is needed to establish “no ozone”.

    • “This is the first time where we’re seeing this interesting behavior over multiple years. We don’t totally understand it,” Trainer said. “For me, this is an open call to all the smart people out there who are interested in this: See what you can come up with.”

      Ah , the old “We don’t totally understand it”, aka we have no idea , see what you can come up with!! Love it.

      That’s just O2 variation. It’s a shame they don’t admit have the same level of ignorance about the unfathomably complex Earth climate system, instead of pretending it’s all perfectly calculable from “basic physics”.

      evaporation :”We don’t totally understand it”.
      condensation: “We don’t totally understand it”
      cloud formation: “We don’t totally understand it”
      storm formation: “We don’t totally understand it”
      precipitation: “We don’t totally understand it”
      global “heating” : we know exactly what is causing and WE MUST ACT NOW.

      • It’s a shame they don’t admit have the same level of ignorance about the unfathomably complex Earth climate system, instead of pretending it’s all perfectly calculable from “basic physics”.

        Exactly my first thoughts. The dichotomy is amazing (the endless repeating of “the science is settled” about gorebull warming).

        • beng,
          I agree – my initial thought, likewise.
          Since the science here is so absolutely settled, can’t they put one of Penn State’s Super-experts onto Mars, to sort it in surely just a few minutes.
          And there’d be prizes, too. Real ones!
          Pity about the inability to bring him – or her – back.

          Auto

    • Mrph. If I still got a copy of the Arizona Red Star (which I don’t), I would roll it up and give you a sharp whack on the nose (which I shall resist, unavailable propaganda rag notwithstanding). We do not “send astronauts to die just to return some Mars dirt” (or Lunar dirt, or Ganymedean dirt, or wherever our explorers decide to go).

      We send them to do the things that humans do – think, experiment, improvise. SAM is a very nice, platinum plated with ebony handles, Philips screwdriver. A human will try a flat blade, a wrench, a hammer, or maybe even a drill key, and get answers.

      • Observer,
        I agree with you. I suspect Joel is/was in the satellite and space probe business, and has no idea the capabilities of human ingenuity.
        Life support does add a whole lot of complexity, but eventually it must be done because that is the end goal after all.
        A geologist with a rock hammer could accomplish what the rover did in a bout 15 minutes, and take the most interesting samples back to a proper lab for analysis. BTW he could erect a sniffer to breath the air while he went about exploring.

        • Yes. The part “to die,” I am afraid, is the remark that triggered me. I get very annoyed at the “everything we need to do we can do with robots” crowd.

          OTOH, I get equally annoyed at the “only send people out and we’ll get so much more back” bunch. Robots are how you decide where it is worthwhile to send people, and where it is not, and do what we need where sending people actually isn’t worth the trouble.

      • The reason people want to send humans there has nothing to do with science. Egos is all it is.
        If your shiny platinum screwdriver breaks, we can send a hundred more there for the cost of sending even one human. Sending that one human (not to mention 4) means a lot of other earth-based science and robotic space exploration, and space telescopes are not being done elsewhere.

        And until some currently unknown new propulsion tech comes along to allow a fast trip to Mars and return, its a suicide mission. And by fast I mean much less than 100 days total out and back.

        • Joel,
          Exploration is a human activity, as expensive as it is. The people that pay the bills just don’t get too excited by robots. Eventually if you don’t send people, the funding will dry up completely. This may annoy you, but it is a fact that must be accounted for when planning these kind of activities.

          • Paul,

            I don’t buy that argument, that we gotta do manned to Mars to keep the public paying for science.

            The public accepts the need to massive amounts of dollars spent on cancer research. Because who has had a friend or family member die from it?
            The public accepts the need to do ocean research because our oceans are so vast and we know so little about what under them.
            For the need for more space telescopes to send us more beautiful pictures like Hubble has done. The pictures are pretty and NASA PR knows it needs keep sending them out for the public interest to keep money for the James Webb telescope going, etc. Cool robotic pictures from Mars helps sell school kids on more Mars rovers. Cool pictures from Saturn, Jupiter, all that sells from the PR standpoint.

            I don’t buy the manned Mars stuff, not with any level of tech we have on the horizon over the next 30 years combined with the radiation lethality problem. Manned Lunar missions are doable, and that’s where we can keep the public interested. The Moon is close enough for a several day trip, and then get the astronauts under sufficient regolith shielding cover to stay there on extended trips with short surface ventures. If a problem arises, they are only several days to get home or for NASA to send a rescue.

            When one does the propellant math for a Manned Mars missions that carries sufficient radiation shielding to mitigate the radiation lethality problem, and then enough oxygen, food and shelter for the humans, you break the bank … literally.

        • The US Government can only buy so much science.
          And if we spend a substantial fraction of that budget over the next 20 years on a low-science return manned Mars mission (that I believe ultimately won’t be executed because of radiation lethality problem), that means a lot of good science doesn’t get funded across all the science disciplines. And I’m not just talking about more deep robotic space explorers. I mean all of science, from Earth-marine science (we know so little about the depths of the oceans as we all know as regular WUWT readers.), new and better gravitational wave detectors, better Earth telescopes and radio telescopes, better space-based solar telescopes to replace STEREO, more biological research fundings, and on and on. We can only do so much. And the money is going to get spent, the high tech, big science jobs are going to be there, but spending it on low science return stuff is nuts.

          Just ask any scientist who’s had their very good research grant proposals fall below the funding line about how much that sucks. Then they watch as hundreds of billions of dollars are wasted on manned-Mars mission fantasies.

          • AHA, as I suspected it’s a “don’t-reduce-my-rice-bowl” argument. Dress it up anyway you’d like.
            I’m all for sending “scouts” ahead, but they are merely scouts and not the settlers.

          • RS,

            When reducing my rice bowl means serving steak and fries to junk science who provide nothing for science… absolutely yes. A Manned Mars mission is nuts, Absolute Nuts.

            No NASA mission manager is going to sign-off on a manned mission to Mars once all the Rad Hazard data and probabilities of death before return are put in front of him/her.

        • Addressing the second point first… It was suicidal for Columbus to try opening an Atlantic route to the riches of the Orient. Which several experts told him, and it was absolutely true. Dumb luck that there were these two big continents (and some nice Caribbean islands between them). The technology is available now to make a manned mission very non-suicidal (barring the demon Murphy).

          First point second… One hundred Philips screwdrivers is still one hundred Philips screwdrivers. Completely useless if what you actually have in front of your robot is a hex head, or even one of those fancy star heads (or even if the problem at hand is a Philips head that your driver either can’t fit in, or just goes whirrr…).

          • Columbus didn’t know what was there, nor did he have robots to send him back pictures and do experiments in situ and radio relay the results back to Spain.

            If you keep sending philips screwdrivers 100 times after the first one broke or became useless, you’re certifiably insane. The point is you can send a 100 screwdriver multi-tools to Mars all over the planet for still less than the cost of one manned Mars mission to single location without the risk of human life.

            Or you can only send 20 multitools to Mars, and use the huge amount left over to buy a few more space telescopes, more robotic missions to the asteroids where we might actually find something useful (cobalt, nickel, etc) that’s not stuck in a planetary gravity well, and a whole lot of Earth-based science.

            Both your rebuttal points… are not.

        • Addendum (to what has not yet shown up, so sorry if they are out of order) – the latter is why I have requested a locking tool cabinet for Christmas this year, one to which I will have the only existing key. Every time I go after a tool these days, I find everything that will not work for the current job…

          • Project Orion could send an entire CITY to Mars. Problem is, all the cities left behind on Earth would be just so much radioactive rubble 🙂

      • I agree with Joel that any astronauts going to Mars won’t be coming back (nor their samples), i.e., they will die going there, landing there, while there, launching to come back, or die on the way back. There are too many opportunities for something to go wrong. They will be outside of Earth’s magnetosphere, the 4+ month journey is too long, the time and distance, and steps involved – landing, safely existing there, launching to come back, travel back – compound probabilities of something going wrong. But, sure, if we throw enough attempts at it, eventually we’d win the quinfecta, but at what enormous costs.
        I would hope that whomever plans to send people to Mars includes on their staff a qualified expert that does nothing but argue that the project will fail from his/her qualified background and experience. For example, in 2012 there was a Carrington level, or higher, CME that fired orthogonal to the direct line to Earth. How do there account for that killing radiation. Another example, with the Sun entering a calm period, cosmic rays will necessarily increase; how do they account for that while going there, while on Mars, while coming back. Other examples – any number of system failures. especially very sensitive life support systems.
        The astronauts will have public schools named after them, so not all is lost.

    • “Any hope this “extra” O2 is biological in origin is unfounded.
      Simply physical chemistry still to be elucidated.”

      Sure… but by the same token, simple physical chemistry is also unfounded. They basically have no idea and are trying to figure out how it could possibly work. Note, that’s “possibly” because even if they can come up with a possible explanation, that doesn’t mean that’s necessarily what’s going on either. 🙂

    • Actually, biological would seem to me to be the easiest explanation. Here on Earth, life exists in all kinds of ‘inhospitable’ surroundings, so why not the other worldly Martian environment?

      I expect there might be a Martian equivalent of photosynthetic life producing O2, and then as O2 ‘builds up in the atmosphere and the temperature ‘warms up,’ some O2 breather organism flourishes turning the O2 back into CO2.

      Why would you expect that it can happen only on Earth?

  2. I’m not saying it was aliens, but it was aliens.
    🙂
    I though that picture of the blue sand dune looking rock formation looked a little organic to me.

  3. Why the mystery and puzzlement about this?
    Methane from Mars is having a drastic impact on Planet Earth’s climate
    AND
    Mar’s methane was put there by Donald Trump.

  4. We have a similar mystery on Earth called the Great Oxygen Catastrophe. Oxygen went from almost absent in the atmosphere to its current level. Almost all life on Earth became extinct.

    A conventional explanation is photosynthesis. There’s not much strong evidence on what actually happened though. There is good evidence that it happened but that’s not the same thing.

    • seasonal swings in gasses are completely different from billion year scale changes.
      The first is physical (outgassing/photo-decomposition), the second is biological-geochemical in origin.
      Simple explanations rarely work in nature.

    • Almost all life on Earth became extinct.

      Almost all life ….. meaning anerobic bacteria, right?

    • You aren’t allowed to conjecture common sense answers to small curiosities involving trace gases. Big Brother is watching. You have been warned.

  5. The changes in O2 concentration as a percentage of the atmosphere composition may be large but as an absolute value they are minuscule.

    It’s a God-awful small affair…

  6. I suppose they have eliminated emanations from the lander itself? Lots of different compounds in close proximity to the sniffer inlet.

  7. Almost certainly to do with soil chemistry. Lots of oxygen there. So….

    1 – This is journalists doing what journalists do – presenting an unlikely story to get readers.
    2 – Glad to see that NASA are finally listening to Lovelock and monitoring planet-wide chemistry to get an insight into how the whole system works. Only took 60+ years…

  8. Curiosity! I looked up several gas analysis from different genetic types of volcanos here on Earth and they don’t have oxygen but are high in CO2. The earthly volcanic gases appear to mostly represent escaping gas accumulation from cooling magma chambers, whereas Curiosity appears to be detecting a biological component. Here’s a question: how can CO2 freeze on Mars if it produces run-away global warming?

    • Genetic volcanoes? Is that like DNA eruptions on Mars?

      They’re talking fluctuations in 1600ppm. And the whole methane kerfuffle is variations on 400 parts per TRILLION.

      But seemingly measuring a biological component…because that’s the story we want to believe.

  9. You can’t fool me. They’ve faked the Viking on Mars. Fake, fake, fake!

    Just look at the picture and tell me that’s not some field in Georgia.
    ;o)

    (I bolded the winky should any humor-challenged CAGW True Believers happen to read that comment. The rest of y’all know I’m kidding.)

  10. Still waiting to read: “For the first time in the history of space exploration, scientists have measured ” … back radiation on Mars with 95% CO2 atmosphere.

  11. Oxygen polymers?
    Does the mass spectrometer see stray peaks at 2, 3, 4….
    times the oxygen mass? I do not know the instrument design details to surmise properly. Will go looking after the sun rises in 5 sleepless hours. Geoff S

  12. “But it didn’t. Instead, the amount of the gas in the air rose throughout spring and summer by as much as 30%, and then dropped back to levels predicted by known chemistry in fall.”

    This is an illogical statement. How is it possible for there to be an increase in O2 by unknown means and then be reduced back to lower levels “…predicted by known chemistry in the fall” (?)

    Re the ‘problem’: Joel O’Bryan mentions the colossal amount of oxygen in the surface soils of the… ahem… Red Planet, and MCourtney notes that a 30% swing in such a miniscule amount of O2 in a thin atmosphere is a …God -awful small affair…” Also CO2 makes up 95% of the atmosphere and O2 is 73% of the CO2 itself in the atmosphere!

    The superabundance of combined oxygen in the atmosphere and the surface soils of Mars suggests it would be, indeed, a conundrum if there was NO variation and departure from ratios with other gases. Transition metals (30 of them in the middle of the periodic table) are a known catalyst for reduction of CO2 and along with water can produce hydrocarbons (methane, alcohol, etc). Oh yeah, they dope these catalysts with organic molecules to increase efficiency in commerialization attempts , but naturally they probably work well enough to change a volume of 0.000nil% in the atmosphere by 30% with summer warmth (the “early” transition metals are the best)

    https://www.sciencedirect.com/science/article/abs/pii/S0010854516305240

    http://www.elementsdatabase.com

    The transition metals include all the common metals and are the red block in the picture of the periodic table. Notably, meteoric dust has high platinum group metals – among the best catalysts.

  13. It is good that the above article makes repeated references to “known chemical processes”.

    Consider that the intense UV radiation on Mars likely places Martian surface chemistry outside of the usual Earth surface chemical processes. That is, nearly all chemical equations used in defining Earth surface mineral chemistry changes do not include UV energy as a key ingredient, appropriately.

    But look at the following various forms of oxides of iron known to exist on Earth (with varying percentages of oxygen):
    FeO
    FeO2
    Fe2O3
    Fe3O4*
    Fe4O5*
    Fe5O6*
    Fe5O7*
    Fe13O19*
    Fe25O32*
    (*associated with high pressure chemistry, such as deep mantle conditions)
    . . . and the following hydroxides of iron known to exist on Earth:
    Fe(OH)2
    Fe(OH)3
    . . . and the oxide-hydroxide FeOOH.

    Throw into the above chemical possibilities the drivers of (1) intense UV radiation and (2) seasonal ambient temperatures, and it is then reasonable that the seasonal percentage change of oxygen in the Martian atmosphere can be explained—at least in part—by the degree to which it is variously bound and released by differing iron-rich surface minerals.

  14. What if Olympus Mons and potentially other volcanic areas of Mars are riddled with ancient lava tubes from gigantic spaces (allowed by the lower gravity) to centimeter tendrils lava capillaries and these are a reservoir of oxides that out gas oxygen in a way that the timing has it arrive a few months out of cycle with the pressure drop?

  15. TonyN’s conjecture seems most plausible to me. What could changes in solar radiation do to the various components of the lander itself to cause the out gassing of O2 or methane?

    • There are not that many materials (such as aluminum, titanium and steel alloys, glasses, multi-layer insulation, electrical insulation, and various adhesive tapes) on the lander that would outgas monatomic or diatomic oxygen. Maybe none at all.

      Generally speaking, long-life materials don’t have oxygen this is easily desorbed or dissociated from the material due to oxygen’s high chemical reactivity and strong chemical bonds.

  16. Climatologists have rejected this instrument-based data because it doesn’t agree with the more reliable output ‘data” of their models. It’s just a travesty that they can’t get instruments to show what they should show.

  17. Honest question.

    What improvements to individual human life on Earth have come from all of space exploration that could not have happened without it?

  18. For the methane fraction, look no further than microbial contamination on the spacecraft itself. Yes, I know, it was sterilized, yada yada yada. Maybe the spacecraft got exposed on its way to, or on, the launchpad. Perhaps a late repair was needed. What’s that saying? “Life finds a way”. As for the oxygen, it varies a lot at any point, but maybe there’s a coupling/de-coupling agent on rocks which have been exposed for millions of years. What sort of organic slime builds up on those, remembering that organic molecules are found in space.

    • The photochemistry of UV-activated perchlorates and its bacteriocidal effects are worth noting.

      Open Access research article

      Abstract
      Perchlorates have been identified on the surface of Mars. This has prompted speculation of what their influence would be on habitability. We show that when irradiated with a simulated Martian UV flux, perchlorates become bacteriocidal. At concentrations associated with Martian surface regolith, vegetative cells of Bacillus subtilis in Martian analogue environments lost viability within minutes. Two other components of the Martian surface, iron oxides and hydrogen peroxide, act in synergy with irradiated perchlorates to cause a 10.8-fold increase in cell death when compared to cells exposed to UV radiation after 60 seconds of exposure. These data show that the combined effects of at least three components of the Martian surface, activated by surface photochemistry, render the present-day surface more uninhabitable than previously thought, and demonstrate the low probability of survival of biological contaminants released from robotic and human exploration missions.

      source: https://www.nature.com/articles/s41598-017-04910-3#Sec6

      The SAM instrument on Curiosity (as well as Phoenix lander’s wet chemistry experiment, and the MRO spectroscopic examinations from orbit) has provided evidence of perchlorate abundance in Martian soil.

      https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgre.20144

    • The UV-activated Mars surface perchlorate concentrations there is like dropping a microbe culture into a concentrated bleach solution. Even the non-living viruses in the culture deposited there are very likely quickly destroyed.

      Published: 06 July 2017
      “Perchlorates on Mars enhance the bacteriocidal effects of UV light”
      https://www.nature.com/articles/s41598-017-04910-3#Sec6

  19. An interesting planetary science article!
    Thanks for posting this CTM. I encourage more science based articles such as this.

  20. How about oxygen levels increase when Mars is closer to Sun, because oxygen is carried with solar wind. The oxygen can come from Sun and it also come from Earth.
    Solar system has a lot of oxygen, 40% of Earth surface rock’s mass is oxygen, same with the Moon and Mars and with space rocks. Any oxidized rock which heated very hot will release oxygen. So impactors will release oxygen and rocks hitting the sun will release oxygen. And Earth atmosphere loses oxygen and Earth loss oxygen oxidizes the Moon, in addition the solar wind in general oxidizes the lunar surface:
    –While the magnetosphere largely protects whatever’s in it from solar radiation, the strength of the solar winds pushes some particles from Earth’s atmosphere into a section of the magnetotail called the plasma sheet – which the researchers say is the most plausible explanation for how oxygen from Earth ends up embedded in the lunar soil.

    “[Earth’s] upper atmosphere consists of oxygen ions that are easily picked up by the solar wind and transported to the Moon,” Terada explained to Rebecca Boyle at The Atlantic.

    “Maybe some portion is implanted on the Moon, and some portion is lost into interplanetary space.” —
    https://www.sciencealert.com/solar-wind-is-blasting-earth-s-oxygen-onto-the-surface-of-the-moon

    And in terms of “some portion”- I would say, somewhere around 90% “is lost into interplanetary space.”

    So Earth’s atmosphere, and impactors in general including impactors hitting the sun itself and it’s all carried by solar wind, and more carried to Mars distance when Mars is closer to the Sun. Of course also, stuff is constantly oxidizing on Mars surface, or Mars impactors heat strip oxygen and later it re-oxidizes.
    And it might also involve Mars going thru periodic comet trail(s) and the “shooting stars” burning up in atmosphere- or dust impacting Mars, itself.
    I would tend to think combination of factors, and I suppose if one is looking the major factor, and one might know {I don’t} when Mars has major meteor shows. Or at least eliminate that factor first- as it might be known.

  21. Because the lander is sampling a very small part of the atmosphere very close to the surface, my money will be on seasonal absorption/desorption into and out of the crustal material that is close to the sampler. Keep in mind as well that the percentages reported are, in my opinion, unlikely to represent the fully mixed atmosphere.

  22. Any ideas on how to terraform Mars and make it more Earth-like? Increase the oxygen and nitrogen, reduce the CO2, and start to transform the soil?

    • Very few Earth plants exist without obtaining water-soluble nutrients from wet soil or from surrounding waters. To the best of our current knowledge, there are no such sources of plant nutrient sources available on the surface of Mars.

      Epiphytic plants (aka “air plants” because they seemingly survive on thin air) such as certain lichens, mosses, and algae might be a possibility for early introduction, but would most certainly have to be genetically modified to survive the intense UV radiation and low absolute pressure at the surface of Mars.

      There is the possibility of liquid water under the surface of Mars, but this is not conducive to photosynthesis that is the basis of all plant life as we know it. Even achlorophyllous (aka holoparasitic) plants, having no chlorophylls themselves, rely on plant hosts that live via photosynthesis.

  23. The cyclic appearance of methane and oxygen does not prove that life exists on Mars, but it is a more promising case than if Mars were as sterile as the Moon. It means that the confirmation of life, if it comes, will be less of a surprise than previously thought.

    Life appeared on Earth almost as soon as the planet cooled enough to allow it. That suggests that the appearance of life even in harsh conditions is not an unlikely event. I expect it to be discovered somewhere in the Solar System and maybe on Mars.

    • Earth has life a mile under rocky surface, Mars would warm enough a mile under it’s surface.
      And Mars could large lakes/very small liquid oceans under 1 mile of Mars surface.
      Many think Earth life might have begun due to volcanic heat, and many think there could life elsewhere in solar system depending on volcanic heat.
      We don’t know much about the life on Earth a mile under the surface, it seems if want to know more about “alien life” in our solar system, it starts by getting more knowledge about “alien life” a mile under Earth surface.
      But if you not interested in microbial life, but instead interested in “higher life forms”, it seems the moons of the gas giants, like Jupiter, would best choice. Mainly due large oceans and large amount of volcanic heat.

  24. “Plasma technology could hold the key to creating a sustainable oxygen supply on Mars, a new study has found. It suggests that Mars, with its 96 per cent carbon dioxide atmosphere, has nearly ideal

    conditions for creating oxygen from CO2 through a process known as decomposition.”

    What about oxygen Plasma on Mars + Solar Winds:

    https://www.google.com/search?client=ms-android-huawei&sxsrf=ACYBGNTHLAeVKb_lut6Fk_rOsA2wNJVgHw%3A1574615841868&ei=IbvaXafZNInQrgTG9LSwAw&q=Mars+oxygen+plasma&oq=Mars+oxygen+plasma&gs_l=mobile-gws-wiz-serp.

    https://www.google.com/search?q=solar+wind+plasma&oq=solar+wind+&aqs=chrome.

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