Mars’ water was mineral-rich and salty

New study finds surface waters on early Mars may have been habitable for microbial life

Tokyo Institute of Technology

NASA's Curiosity rover has obtained the mineralogical and chemical data of ancient lake deposits at Gale Crater, Mars. The present study reconstructs water chemistry of the paleolake in Gale based on the Curiosity's data. Credit NASA

NASA’s Curiosity rover has obtained the mineralogical and chemical data of ancient lake deposits at Gale Crater, Mars. The present study reconstructs water chemistry of the paleolake in Gale based on the Curiosity’s data. Credit NASA

Presently, Earth is the only known location where life exists in the Universe. This year the Nobel Prize in physics was awarded to three astronomers who proved, almost 20 years ago, that planets are common around stars beyond the solar system. Life comes in various forms, from cell-phone-toting organisms like humans to the ubiquitous micro-organisms that inhabit almost every square inch of the planet Earth, affecting almost everything that happens on it. It will likely be some time before it is possible to measure or detect life beyond the solar system, but the solar system offers a host of sites that might get a handle on how hard it is for life to start.

Mars is at the top of this list for two reasons. First, it is relatively close to Earth compared to the moons of Saturn and Jupiter (which are also considered good candidates for discovering life beyond Earth in the solar system, and are targeted for exploration in the coming decade). Second, Mars is extremely observable because it lacks a thick atmosphere like Venus, and so far, there are pretty good evidence that Mars’ surface temperature and pressure hovers around the point liquid water–considered essential for life–can exist. Further, there is good evidence in the form of observable river deltas, and more recent measurements made on Mars’ surface, that liquid water did in fact flow on Mars billions of years ago.

Scientists are becoming increasingly convinced that billions of years Mars was habitable. Whether it was in fact inhabited, or is still inhabited, remains hotly debated. To better constrain these questions, scientists are trying to understand the kinds of water chemistry that could have generated the minerals observed on Mars today, which were produced billions of years ago.

Salinity (how much salt was present), pH (a measure of how acidic the water was), and redox state (roughly a measure of the abundance of gases such as hydrogen [H2, which are termed reducing environments] or oxygen [O2, which are termed oxidising environments; the two types are generally mutually incompatible]) are fundamental properties of natural waters. As an example, Earth’s modern atmosphere is highly oxygenated (containing large amounts of O2), but one need only dig a few inches into the bottom of a beach or lake today on Earth to find environments which are highly reduced.

Recent remote measurements on Mars suggest its ancient environments may provide clues about Mars’ early habitability. Specifically, the properties of pore water within sediments apparently deposited in lakes in Gale Crater on Mars suggest these sediments formed in the presence of liquid water which was of a pH close to that of Earth’s modern oceans. Earth’s oceans are of course host to myriad forms of life, thus it seems compelling that Mars’ early surface environment was a place contemporary Earth life could have lived, but it remains a mystery as to why evidence of life on Mars is so hard to find.

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Reference:

Keisuke Fukushi1*, Yasuhito Sekine1,2, Hiroshi Sakuma3, Koki Morida4 & Robin Wordsworth5, Semiarid climate and hyposaline lake on early Mars inferred from reconstructed water chemistry at Gale, Nature Communications, DOI?10.1038/s41467-019-12871-6

1 Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa, Ishikawa, Japan.

2 Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan.

3 National Institute for Materials Science, Tsukuba, Ibaraki, Japan.

4 Division of Natural System, Kanazawa University, Kanazawa, Ishikawa, Japan.

5 Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA.

Tokyo Institute of Technology (Tokyo Tech) stands at the forefront of research and higher education as the leading university for science and technology in Japan. Tokyo Tech researchers excel in fields ranging from materials science to biology, computer science, and physics. Founded in 1881, Tokyo Tech hosts over 10,000 undergraduate and graduate students per year, who develop into scientific leaders and some of the most sought-after engineers in industry. Embodying the Japanese philosophy of “monotsukuri,” meaning “technical ingenuity and innovation,” the Tokyo Tech community strives to contribute to society through high-impact research.

The Earth-Life Science Institute (ELSI) is one of Japan’s ambitious World Premiere International research centers, whose aim is to achieve progress in broadly inter-disciplinary scientific areas by inspiring the world’s greatest minds to come to Japan and collaborate on the most challenging scientific problems. ELSI’s primary aim is to address the origin and co-evolution of the Earth and life.

The World Premier International Research Center Initiative (WPI) was launched in 2007 by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) to help build globally visible research centers in Japan. These institutes promote high research standards and outstanding research environments that attract frontline researchers from around the world. These centers are highly autonomous, allowing them to revolutionize conventional modes of research operation and administration in Japan.

Kanazawa University has contributed greatly to higher education and academic research since it was founded in 1949 as the leading comprehensive university on the Sea of Japan coast. The University has 3 colleges and 17 schools, 7 graduate schools offering courses in subjects from humanities and social sciences to natural sciences and life sciences. The University is located in Kanazawa, Ishikawa – a city where tradition and innovation are existing in harmony. Kanazawa University is divided into two main campuses: Kakuma and Takaramachi for its approximately 10,100 students including over 650 from overseas.

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54 thoughts on “Mars’ water was mineral-rich and salty

  1. Maybe, once on Mars, they should drill deeper as they are able now and will maybe surprised about their findings. Or even not. 😀

    • One might suspect given the high mineral content of martian water that some fossil evidence might exist of even large conglomerations of micro-celled orgasms such as stromatolites or other primitive structures.
      Perhaps surface water was not as prevalent in Mars’ history to allow solar energy interaction.
      Carbonates on Mars are primarily magnesium carbonates rather than Earth’s calcium carbonates, but there are very few carbonate outcroppings on Mars. Given Mars’ sedimentary formations should we expect there are caverns caused by erosion and water flow.

  2. “Mars’ water was mineral-rich and salty…”

    I thought that water was pretty much a universal solvent. And that water on Mars would have been in contact with rocks and natural salts for many aeons before it finally disappeared – from the surface at least.

    So surely the last remnants were going to be VERY ‘mineral rich and salty’?

    • Exactly. Probably, no matter what Mars actually looked like, some sediment deposits on Mars are likely going to look a lot like the sediments around the Dead Sea, Utah’s Great Salt Lake, and such. Probably much larger number of samples is needed before proclaiming “Mars Oceans were …”

      • I was under the impression, Mars lacks sufficient gravity to support an Earth like atmosphere.

        Perhaps Mars was in a different orbit in the past?

        • As I understand it, it isn’t the gravity, but the lack of a strong magnetic field that did in the martian atmosphere. At some point in the history of Mars, the core solidified, thus ending any magnetic dynamism the planet may have had. Once that happens, the atmosphere is pretty swiftly blown away by the solar wind.

          • Density and mass in motion, magnetic liquid core makes sense yet what could have possibly solidified it?

            Beyond that simplistic question, why are we keen on colonizing a planet that can never again support an atmosphere?

            I was also under the impression, Mars has a polar ice field. If it does, why are we going gaga over salt and minerals?

      • Once you’re up there, distance is simply a matter of time. You don’t need much more energy to go to Titan.

        Incidentally, total oil usage for the Earth per year is around 100m barrels . A barrel is only about 0.16 of a cu meter. So a quick calculation suggests that a cube 250m x 250m x 250m would contain enough hydrocarbon for a years consumption. Should be easy enough to get that into orbit around Titan (0.138 G)

          • Somewhere back in the stacks, I have the book by Arthur C. Clarke where he posited hydrocarbon mining of Titan.

            Now, as I remember it (several years ago that I read it), the product was being delivered to various space habitats, not to Earth’s surface. Which is reasonable – it takes just as much energy to soft land on Earth as it does to get off of it.

            (Let us not think of aerobraking a 250 meter cube every day. Murphy would love that idea – it probably would not be long before a city or two was obliterated by a gigantic fuel air bomb Oops!)

          • Writing Observer:
            it takes just as much energy to soft land on Earth as it does to get off of it.

            No. Almost all the “energy” needed to slow down orbital speed to soft speed (including the final parachutes) is provided by atmospheric drag & dissipates as heat.

          • Writing Observer, to add to my response, your statement would indeed be true for taking off/landing on an airless world — no atmosphere present to provide braking.

        • Daily oil consumption is about 100,000,000 bbls, not annual. That does not include natural either. Only oil.
          So you would need a DAILY shuttle of those 250 meter spheres, to supply NEARLY as much energy as we now use from oil.

  3. There’s a series of questions relating to the red planet that our watermelon alarmists should consider:

    When our carbon dioxide emissions kill off the planet, is our only hope evacuating to Mars and living in biospheres?

    Do we have to embrace a green, vegan diet there, growing all our own food?

    Do we also embrace glasshouse technology, pumping each massive biosphere full of carbon dioxide to grow enough of this food at much higher concentrations than we had on Earth?

    I suspect that answers to the third question might be hard to get.

  4. ‘pH (a measure of how acidic the water was),’

    Or possibly how alkaline it was – just shows how inbuilt the bias is in the system.

    • half full or half empty?
      how about:
      pH is a scale used to define the relative acidity or alkalinity of a water based solution. It ranges from 0 to 14, with 7 being the neutral point.

      To be more pedantically specific, the pH is the logarithm (to the base 10) of the reciprocal of the hydrogen ion concentration, [H+]. The pH is approximately equal to the negative logarithm of the H+ ion concentration expressed in molarity.

  5. Why not focus a mission on finding at least one hot spring or ancient hydrothermal vent anywhere on the whole planet?

  6. On earth, the biosphere extends, in someplaces, to at least a few thousand feet below the ground surface where microscopic life forms inhabit tiny cracks and pore spaces containing water.

    Perhaps similar refugia exist below the surface of Mars.

  7. The most amazing thing to me is, with an entirely CO2 atmosphere, Mars isn’t remotely warm enough for liquid water, and in fact, C02 freezes on its surface. Why, it’s as if all that global warming can’t keep anything warm with 100% C02.

    Don’t get me started on “might have supported life”, we hear that with every report on Mars. I think it’s just a come on for more research dollars, kind of like invoking “climate change” in sociology papers.

  8. It has become fashionable to suggest that Earth was seeded with life from Mars or some distant asteroids. I prefer to credit this beautiful planet with the creation of its own life rather than being the recipient of life from some distant inhospitable world. I think there is an argument that, on the assumption that life arose spontaneously on this planet at some point in time, then it was an event that only happened once. Surely if it happened multiple times then the life resulting from such spontaneous events would not always would be based on self replicating DNA/RNA.

    • ” I think there is an argument that, on the assumption that life arose spontaneously on this planet at some point in time, then it was an event that only happened once. Surely if it happened multiple times then the life resulting from such spontaneous events would not always would be based on self replicating DNA/RNA”.

      Quite possibly, but if so the other options weren’t as succesful so only beasties using DNA/RNA survived.
      Similar to humans…there were other varieties but only sapiens survived [so far].

  9. “…to the ubiquitous micro-organisms that inhabit almost every square inch of the planet Earth

    ,

    Yup. Believe me, they did not stop trying at the last square inch. Open volcanic lava is your best chance of finding a square inch not covered by biota and its products. An oceanic biofilm producing carbonic anhydrase can potentially increase the rate of atmospheric CO2 neutralisation by up to 7 orders of magnitude.

    That’s up to 10,000,000 times faster. Lets assume it’s a lot less. But how much less? Can anyone still believe simple physical models about the chemistry of the biosphere?

  10. “Second, Mars is extremely observable because it lacks a thick atmosphere like Venus, and so far, there are pretty good evidence that Mars’ surface temperature and pressure hovers around the point liquid water–considered essential for life–can exist.”

    Huh? Due to its greater distance from the sun, the average surface temperature on Mars is estimated as -60 C, well below the freezing point of water (0 degrees C). Mars is much smaller than the Earth and has much weaker gravity, so it cannot hold a thick atmosphere. Even at 0 C, water has a vapor pressure of about 6.1 millibars, meaning that any liquid water present would rapidly boil away (or ice would sublime) if exposed to sunlight.

    The only place on Mars where spacecraft found evidence of water was near the Martian south pole, where a small ice cap was found, which does not receive enough sunlight to melt or sublime it. Away from the poles, the Martian surface receives enough sunlight so that any ice would have sublimed into the very thin atmosphere. The Martian atmosphere is mostly carbon dioxide (molecular weight = 44), so that water vapor (with its lower molecular weight = 18) would tend to rise through the Martian atmosphere and escape into space. This doesn’t happen on Earth, since there is so much water in the oceans that the atmosphere over them tends to become saturated, and water vapor condenses and falls back to the earth as rain.

    This does not mean that there was never water on Mars in the distant past–Mars could have had hot springs that could have formed rivers, or seas at low points. But with the weak gravity and low atmospheric pressure, liquid water would have evaporated relatively quickly, and would not be present at a high enough partial pressure to condense and rain back to the surface, so it escaped into space long ago.

  11. “… evidence of life on Mars is hard to find.” Could it be hard to find because it was never there?

  12. It never ceases to amaze me that science cannot be reconciled with the notion of the existence of a God or an after life.

    Well, we certainly know the after-life exists thanks to years of public work by former renowned member of the Spiritualist Association of Great Britain, the famous Doris Stokes.

    It makes sense, then, that if an after-life exists, then why not God? And if God exists, then why not the reality that this world could be the only place where life exists?

    We are, after all, dealing with the greatest mystery, right?

  13. [ ] minerals observed on Mars today, which were produced billions of years ago:

    [ ] oxygen [O2, which are termed oxidising environments; the two types are generally mutually incompatible])

    – the Red Planet. Ferron, the oxygen transporter.

    – as in human blood cells: blood-red, oxygen transportable by Ferron.

    Planets Earth and Mars, strong relationship

  14. Patrick MJD January 22, 2020 at 3:29 am

    Oil!

    ____________________________________

    Why not. Uninhabitable Albania has oil fields too:

    https://www.google.com/search?q=albania+oil+fields&oq=Albania+oil&aqs=chrome.

    Heavy Metals Albania –

    https://www.google.com/search?client=ms-android-huawei&sxsrf=ACYBGNRolipbnL3Q5pkbACtxgWSp0xdIgw%3A1580735783642&ei=Jx04Xq72JsyqrgSOu54Q&q=Albanian+soil+unhabitable&oq=Albanian+soil+unhabitable&gs_l=mobile-gws-wiz-serp.

    ____________________________________

    And still –

    – Albania is a land of the books And Albania is a land of the Universities

    – while till today no one reads Albanian Universities books cause no other known peoples language is related to the Albanian language.

    What publishing company translates and distributes books from a 2 mil. People land.

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