10 Quick Thoughts about Water on Mars

By Corey S. Powell | September 28, 2015 12:57 pm
Here there be water? Dark streaks on Mars (presented in false color for clarity) indicate likely flows of salty water on the planet. Credit: NASA/JPL-Caltech/Univ. of Arizona

Here there be water? Dark streaks on Mars (presented in false color for clarity) indicate likely flows of salty water on the planet. Credit: NASA/JPL-Caltech/Univ. of Arizona

NASA generated quite a bit of buzz today with the apparent discovery of flowing water on Mars. Now to anybody who follows science news–especially news about space and alien life–those words may sound awfully familiar. It seems like NASA has been discovering water on Mars every year for the last decade. This time really is different, however. For one thing, scientists are talking about water on Mars right now. For another, the evidence is much stronger than it was in past reports; I wrote about some of those earlier speculations here.

Although the news just broke earlier today, there has already been extensive discussion of the results online. I’ve read through the early conversations (so you don’t have to). Here are some of the key things you should know. I’ll start with the bad news, since I always like to get it out of the way first.

It’s not exactly Club Med on Mars.

This is not water just sitting on the surface. Let go of any images of lakes and rivers; the atmospheric pressure on Mars is so low that liquid water will immediately vaporize on the surface. The evidence is for seeps of salty water that flow down steep slopes, mostly the rims of craters, forming dark streaks.

The water is cold. The streaks–technically known as recurring slope lineae–appear at temperatures as low as 10 degrees below zero Fahrenheit (-23 degrees Celsius). So also let go of any images of hot springs on Mars.

The water is super-salty. You may be wondering how water stays liquid at -10 degrees F; this is the answer. Just as salt can melt ice on your sidewalk in sub-freezing weather, it can keep water liquid at the frigid temperatures of Mars. Other probes already found perchlorate salts on the Martian surface; the detection of these hydrated salts in the dark streaks, made by the Mars Reconnaissance Orbiter, was the clinching evidence that the dark streaks are formed by salty water.

Salty Mars water is probably not suitable for life. This is the biggest downer in the NASA announcement: Percholorate-saturated water makes a lousy drinking fountain for Mars microbes, so this detection doesn’t mean that we’ve found a viable habitat on Mars.

OK, ready for some good news?

Where there is some water, there is probably more. We don’t know if the salts are absorbing water from the atmosphere or if the water is coming from some other source. Either way, today’s news indicates that there is more water on Mars, moving in a more complicated cycle, than scientists thought before. That increases the likelihood that there are other spots (underground, almost certainly) that have more life-friendly water sources. In the words of Jim Green, NASA’s director of planetary science, “Mars is not the dry, arid planet that we thought of in the past.”

We’re going back to find out. NASA’s Mars2020 rover (planned for–you got it–2020) will conduct sensitive measurements of the surface and atmospheric chemistry. The rover will also carry ground-penetrating radar that might be able to detect buried aquifers.

This news greatly bolsters the case for Mars sample return missions. Both NASA and the European Space Agency are nominally committed to bringing pieces of Mars back to Earth, but NASA scrubbed a crucial precursor mission. Finding water on Mars boosts the scientific rationale for getting the program back on track. Labs on the ground can perform vastly more sophisticated analysis than is possible with a small, remote-controlled robot.

We know how to get to the right places. Remember, the wet streaks are mostly on steep slopes where rovers, or even astronauts, would have a tough time exploring. But NASA’s Jet Propulsion Laboratory has been experimenting with a variety of cliff-bots: climbing robots that could make their way down a crater wall and collect samples from the wet spots. All this can happen long before astronauts arrive. Keeping things sterile might actually be a harder task. NASA has strict “planetary protection” protocols to make sure the agency doesn’t accidentally contaminate Mars with Earth microbes before we can find any local life.

Water is an abundant resource. Today’s announcement is just one more reminder that the fundamental ingredients of life–water and organic compounds–are extremely common throughout the solar system, and throughout the universe. There are water and carbon compounds in comets. There is water on the moon. There is water at Mercury’s north pole! It’s not that surprising, then, that there are places where liquid water persists on Mars. If life ever got started there, it probably still has many sheltered places where it could still be holding on.

Finally, Mars is not the only place to look. Not by a long shot. Jupiter’s moon Europa has a huge ocean, more than twice as large as all of Earth’s put together, hidden just beneath its icy crust. Saturn’s moon Enceladus has a buried ocean, too, and it shoots out geysers that contain salts and organic compounds along with water. Another moon of Saturn, Titan, is covered with lakes of liquid methane and sand dunes made of tar; its whole surface is one enormous carbon chemistry lab.

All of these places are out there, waiting to be explored. The cost of going is not so great. The potential for discovery–truly revolutionary discovery–is huge.

Follow me on Twitter: @coreyspowell

  • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

    Let’s look at facts, then draw the conclusion that a “wet” Mars is tremendously inhospitable to life. Human physiological saline is NaCl 8.9 g/liter, 0.88 wt-%, 0.152 molar, ∼290 mOsm/kg H2O.

    Geophys. Res. Lett. 36, L10202 (2009), doi:10.1029/2009GL037497
    Mg (-67 °C, 44 wt-%) and Na (-37 °C, 52 wt-%) perchlorate eutectics.

    Icarus 207 675 (2010)
    Na (-35 °C, 9.2 molal), Mg (-71 °C, 3.5 molal) , Ca (-75 °C, 4.2 molal) perchlorate eutectics.

    J. Cosmol. 5 930 (2010)
    H2O-H2O2 eutectic -56 °C, 61.2 wt-% peroxide

    Nothing imaginable can live in any of that. They are intensely dehydrating for concentration (water fugacity or chemical activity; osmotic pressure), and violently oxidizing.

    • TLongmire


      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        Aquaphobe, osmophage, peroxisome, Arean- lover, cite fright mite.

        • TLongmire

          Your chant rings maddeningly. Constant adherence to consensus is void. Consciousness expands freely

          • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

            Mine are refereed journal citations. NASA has its own journals because legitimate academics enforce factual standards. Now put your thumb back in – the noise is bothersome.

          • Emkay


          • bwana

            Yet another narrow, narrow minded comment. Come on Al, think beyond your little world!

    • http://www.facebook.com/Kieseyhow Kieron Seymour-Howell

      Good sources, but the possibility still exists life may have found adaptive mechanisms for thriving in such environments. If microbes can breed in concentrated acid pools in geothermic regions here on earth. Or, in the heat and pressure of thermal fissures and vents on the ocean floor. It is likely to have gained a foothold in other inhospitable environments elsewhere as well. I make no assumptions really, other than to take notice of this development with curiosity and interest.

      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        The “violently oxidizing” part is something of a challenge for biological molecules re unsaturated fatty acids and nitrogen heterocycles. Peroxisomes are exotic. Anammox planctomycetes are downright alien re anammoxasome ladderane membrane lipd components, doi:10.1016/j.bbamem.2009.04.008, 10.1159/000346547, 10.1128/MMBR.05025-11

        • http://www.facebook.com/Kieseyhow Kieron Seymour-Howell

          Yes indeed. But life (understood as an arrangement of molecules that process energy in order to resist entropy) is tenacious and highly adaptive. It is entirely possible for highly stable proteins to bind themselves with more inert matter and form shells that resist the oxidizing effects. I think that biology is far from an advanced science on this planet. It will be interesting indeed to see what discoveries unfold in the future.

    • Emkay

      fugacity (fjuːˈɡæsɪtɪ)
      1. (General Physics) Also called: escaping tendency thermodynamics a property of a gas, related to its partial pressure, that expresses its tendency to escape or expand, given by d(logef) = dμ/RT, where μ is the chemical potential, R the gas constant, and T the thermodynamic temperature. Symbol: f
      2. (Botany) the state or quality of being fugacious

    • bwana

      “Nothing imaginable can live in any of that.” I have a very active imagination and just because we can’t imagine a life form doesn’t mean it can’t exist somewhere in the universe!?

      Your argument works if we assume water is the essence of life but…

      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        Propose credible non-aqueous biochemistry – cell membrane, metabolism, or genetic information storage.

        • bwana

          I do believe you’re thinking far too close to home…

        • bwana

          Life has a lot of surprises AND we’re really limited in what we know at this point in our short existence…

    • Oslo, Norway

      Look, Al, just because you cannot imagine it, doesn’t mean that it can’t exist. Life’s ability, in any form, to adapt to its surroundings is where the amazement exists.

      • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

        Propose in situ survivable biochemistry – cell membrane, metabolism, or genetic information storage. The Atacama desert hosts extremophies that live within surface salt extrusions, They don’t get 30 rads/year of ionizing radiation, solar hard UV, or live in saturated perchlorate solution.

      • Prentice Price

        Look, Oslo, and that’s where the amazement should end. Enough with the trillions spent on something that will never see fruitation. It’s life on earth that we should be concerned with. Take care of this planet and you won’t need another. Things are really getting stupid!

        • coreyspowell

          It makes me sad to see comments like this. First of all, the costs of the MRO probe that made the discovery is about $50 million/year–hardly “trillions.” Second, NASA’s budget (as a fraction of federal spending) has dropped 90% in the last 45 years. Did those cuts save the Earth?

          But the most important point is this: Space exploration in an inspirational project that has yielded great engineering advances and that has probably done more to advance education in this country than the vastly larger expenditures of the Department of Education. Much of what we know about taking care of this planet comes from studying it (and other planets) from space.

          In the long run, turning away from exploration and inspiration is actually the truly costly strategy.

          • OWilson

            Surely cost versus benefit is always a valid argument.

            Whether it be a personal expenditure, a family expenditure, a City, State, Federal or Global (U.N.).

            The old argument that it only amounts to ” a few pennies a day”, is why we have a growing and unsustainable debt, that nobody knows what to do with.

            There are many lobbies for favorite “pennies a day” pet projects, all of which make sense in isolation, but together, in accumulation, are completely out of control.

            My personal favorite is “a few pennies a day” to study how to pay as we go and not shove our selfish “wants” on to the generations unborn. :)

          • Prentice Price

            OK, $50,000,000 instead of “trillions”,. I stand corrected. But it only cost .50 cents a day to feed a hungry child in a poor country. Can you still justify this much cost to just “study” another planet without knowing if it will ever do 1 single thing to help this planet? Also, while it is true that it helps the education of this country in space exploration, is this really what we should be teaching our children?

          • Mike Richardson

            I’m all for donating money to feed children, and do so. I also donate to space and science advocacy groups. There’s no reason why you can’t do both. And if you’re concerned about societal priorities, you might do better to urge a reduction in massive military spending, or tax breaks for corporations or the very wealthy, not the comparatively small amount of funds you’d save by doing away with the space program. In the long run, knowledge about our cosmic neighborhood will give us insight into resources which could alleviate many of the problems with which our current civilization struggles. As for what we should teach our children, my thought on the matter is, “As much as possible.”

          • coreyspowell

            Well said!

          • Prentice Price

            “Resources which COULD alleviate many of our problems”. So would you agree that it’s just a wish to bring all thee resources back to earth? I don’t dispute the fact that the resources are there in space. But I do dispute the fact that enough will ever be brought here to make a difference. The shipping costs are too great and that doesn’t make sense.

          • coreyspowell

            Let’s crunch the numbers. $0.50/day to feed a child. Let’s say there are a billion hungry children around the world. We could feed them all for about $150 billion/year. That’s less than 5% of the federal budget. So why don’t we do it? Is it really because we are spending 1/3000th that amount on exploring Mars?

            My point is that it is meaningless to talk about these numbers without looking at our overall priorities. The notion that the only way to do charitable work around the world is by sacrificing one of the most inspiring things the government does is a fallacy–and a sad one, at that.

          • REALLY?

            First of all, let’s ask some other questions. Should David Beckham, Kim Kardashian, or some other vaguely interesting “celebrity persona” get payed hundreds of millions of dollar every year for just standing there half naked or kicking a ball and chasing after it? Should Tiger Woods be a Billionaire for hitting golf balls just a little better than you and i can?
            Should Dr. Phill who is not trained psychiatrist analyze and shame random people on TV and get payed more than the Head of a whole Space Agency?

            Yet you (I assume you are an American) and generally all over the world people promote such non-sense as described above. Thanks to capitalism, we all worship the obscene undeserved wealth and flashing of it to the faces of less fortunate with glitz and glamour. We worship such idiocy as expensive cars and material wealth and luxury escorts for wives so much so, that you might have the silver spoon fed Donald Trump for the President in a year or so…

            Entire NASA budget from it’s inception to this day is equal to merely single year budget of pentagon nowadays (add or cut few months). Yet what has the NASA brought us? Knowledge, solid science, enlightenment and PROGRESS for HUMANITY AS ONE. As to what the Pentagon has brought us, well check the news. There ought to be few hundred more headless corpses today from the instability the pentagon has spread through out the world. If there isn’t don’t worry tomorrow there will be thanks to muslim lunatics and their crusading counterparts.

            How about we all cut on Jeb Bush or Clintons Obscene Campaign Budgets and feed your hungry children, how about Kim Kardashian takes another photo of her oiled behind and feeds the hungry children? And after that let’s cut on what already is a shamefully meager support for Science and Progress that will save Humanity. Jesus won’t save the muslims and Mohammed won’t save christians, Buddhists won’t save any one, when we face the doom God if he exists won’t bother to lift tip of his finger. Grow up.

          • Prentice

            Really! Really? The fact of the matter is the celeberties you refer to make it on their own. They don’t rely on sucking the tax payers dry. I’ve worked for my living all my life and donate regularly to the poor as Uncle Sam does and should. Not as someone who sits behind a telescope relying on someone else’s hard earned money and speculates what MAY be way out in space. If they want to know what’s really in space they should look no further than their own mind!

        • Karthikeyan Alagirisamy

          Well Price, for once let me assume you live in North/South America, I understand that Amerigo Vespucci & Christopher Columbus in an attempt to find new short route to India found your home. Hope you would appreciate that stuff. Like wise, why not hope NASA finds something while searching for something else. After all we are over whelming this piece of rock that we call Earth. Lets find new home :) Why stop that :)

          • http://www.facebook.com/Kieseyhow Kieron Seymour-Howell

            I hope you do not really still believe that farsical propaganda about Columbus discovering America. :)

    • Andy Extance

      I agree that this for life to exist in this environment would be a huge challenge – I stop short of calling it impossible. But perhaps if we don’t find life we might find something almost as good, or even *better*: we may find molecules that are on the way to becoming life, that will confirm one of the theories of how life originated on Earth, or even suggest new ones.

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    Let me show you superfast ways to get paid some money on weekly basis by completing# basic tasks on-line from comfort of your home for 3-4 hrs a day ~ Check >my disqus to see more information

  • Me

    ‘The cost of going is not so great’?? You planning to foot the bill then?

    • coreyspowell

      Yes, I would happily absorb the 0.02% tax increase it would take to mount serious missions to Europa, Mars, Titan, and Enceladus.

      • Me

        I meant by yourself. :) Seriously, I am all for this kind of thing too. But sadly, every time I think about someone trying to actually GO, I arrive at the same conclusions. I just can’t imagine it happening. Let’s say for discussion that 10, or even 5, people would be spending 10 years going, studying, and returning. This means that EVERY ONE of those people has to have basically ‘everything’ they’ve consumed, every medication they’ve taken, etc. over the past 10 YEARS with them when they leave. 50 person-years worth of groceries. The ship would need to be enormous. Then it will need an enormous power plant. And enormous fuel. No ‘stripped down chevy’ space shuttle will make such a trip. And, what if something totally unexpected happens when they get there? What of the doctor sent with them dies, or needs surgery himself? A million what ifs.

        The thing about discovery and expeditions, to my reckoning, is that just because we might think we can, doesn’t always mean we should. How many ‘explorers’ have died horrible deaths over the centuries just because they had no clue that going was such an incredible risk?

        My vote then is to fix what’s wrong here first, and learn more about how to survive along the way. Then maybe ‘someday’ consider such a voyage when we have the technology and education behind us to better avoid catastrophic uncertainties. At least until we can manufacture life’s daily necessities virtually from nothing. Until then, let the unmanned probes handle the risky business of exploration.

        • Daniel San

          And just imagine if your ancestors had been that short sighted. Everyone knows the risks and the costs and they are well worth it to add to human knowledge.

        • Paul Pi

          Luke: “I don’t believe it.”
          Yoda: “That is why you fail.”

          • StanChaz

            Yes, but you only believe that,
            said Luke, with a sly smile.

      • Prentice Price

        I vote we send coreyspowell with a one way ticket to The Outer Limits and beyond.

  • Mike Richardson

    Sounds like a good environment for halophiles. Even the Dead Sea isn’t dead for organisms evolved in a hypersaline environment. Hopefully NASA will focus on some of these outflow channels in future missions, and plan for some fairly exotic chemistry in their tests for biomarkers.

    • shonda.johnson2

      Allow$ me to show you a best way you can make a lot of money by completing basic tasks online from your couch for few short h /day / Check it out on following site …u­­ltimatewaysforearnings98­­7294857928­.­blogspot­.­in

  • http://www.facebook.com/Kieseyhow Kieron Seymour-Howell

    Very interesting development. It is my opinion (based on science, physics of course) that water is fairly common in space, and it is likely to be found wherever there is enough mass to keep it from evaporating into the vacuum of space. And, where there is water, there is a far greater probability of some form of life that is carbon based, or perhaps even more exotic. But speculation is amusing at best, only time and research will tell the real story.

  • Robert Whitney

    Can you imagine a baseball stadium (covered of course) there? Otherwise players would send baseballs into orbit.

    If we could terraform Mars, how would we be able to keep the atmosphere from bleeding away? Could we bombard it first with asteroids to increase it’s mass and possibly increase it’s gravity or, is that even possible?

    Obviously I am not a scientist but just a curious human wishing we could do those things. Waiting to see the movie “The Martian”.

  • boonteetan

    NASA might have known more about the condition of water on Mars. More will unfold. One can wait before drawing any definite conclusion.

  • Ever García

    Very intersting. Well done, NASA! 😉

  • Mecca Andropolis

    Maybe that’s some water that future space-travelers can convert to Lysol to use for disinfecting their equipment.

  • https://www.researchgate.net/profile/Ma_Padmanabha_Rao M.A.Padmanabha Rao, PhD(AIIMS)

    NASA’s success in exploring space is remarkable.
    HOWEVER I EXPRESS THREE DOUBTS: The sharp lines on the extreme left in the picture shown here raise three doubts on the apparent discovery of flowing water on Mars.
    1 Intially, the lines show a raise. We know water flows when the ground level is low.
    2. The lines ended at one point against what happens in a continuous flow of water, say in river.
    3. On any island formed in between a flowing river, we normally see flat bed filled with sand with stones lying here and there In the current situation, sharp lines are seen.

    Therefore, the experts may please examine these points.

    • http://www.facebook.com/Kieseyhow Kieron Seymour-Howell

      Sometimes water, or other fluid, will flow against gravity or pressure, due to capillary action, or a “wicking” effect from the denser concentration towards a lower concentration as in osmosis or diffusion. Also some chemicals and salts or acids actually attract water and provide another force to move the fluid due to the attraction of the electrons sharing orbits with other matter nearby. Then you have the ions involved in the process also. Then again also, is the “pull” from the tension of the similar molecules as the fluid evaporates into the atmosphere, such as how trees move water up through their internal structure. There are many complex factors at work involving both physics and chemistry to consider before an accurate model is realized. This is why future rovers will be designed to negotiate steep inclines and sheer cliff faces to take samples and measurements to better understand exactly what is going on. Much of what we read about it as much assumption as actual observation, just like here on this planet.


  • StanChaz

    Who cares about water?
    NASA has –for years–
    refused to admit their
    REALLY important discovery
    of Martian BEER.
    We want the truth!

    • StanChaz

      we also have the immense NASA conspiracy to hide the fact that the Mars Rover discovered half-eaten Twinkles strewn over the Martian surace. Of course, this discovery negates the possibility of INTELLIGENT Martian Life, but we still demand the truth!

  • Gogoboz

    One thing I always wonder, if human could find an asteroid or planet that allow mining, will those minerals eventually help distroyed earth due to the lost balance and contaminated proportions of minerals constitute the planet formation? If discovery of drinkable of water on found planet, aren’t we going to sensitized the local living before colonized it? If not, why we waste so much time to explore it in the 1st place?

  • Jackson

    Uncle Al, clearly you love to hear yourself talk and you believe you are vastly intelligent. I can tell with certainty that you are a blow hard. If you can’t imagine something, then it doesn’t exist? Go back to your calculator and let the rest of us continue exploring.

    • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

      If you are threatened by peer-reviewed literature citations, you should be. Physical reality is not My Little Pony, with or without an extruded nether rainbow.

  • Ireen Hilty

    How amazing is this. Water on mars shows that maybe there could be life on the planet or we could go there and investagate even more than you can imagine.

  • Karthikeyan Alagirisamy

    50 KiloMeters to alien waters, so close after 50+ years of search, now wait for sterilization because of a pact 50+ years old!!! phew , curious, adrenal pumping stuff and ofcourse irritating + frustrating


Out There

Notes from the far edge of space, astronomy, and physics.

About Corey S. Powell

Corey S. Powell is DISCOVER's Editor at Large and former Editor in Chief. Previously he has sat on the board of editors of Scientific American, taught science journalism at NYU, and been fired from NASA. Corey is the author of "20 Ways the World Could End," one of the first doomsday manuals, and "God in the Equation," an examination of the spiritual impulse in modern cosmology. He lives in Brooklyn, under nearly starless skies.


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