Mars has a lot of water. Who knew?


Two years ago, planetary scientists reported the discovery of a large saltwater lake under the ice at Mars’s south pole, a finding that was met with excitement and some scepticism. Now, researchers have confirmed the presence of that lake — and found three more.

The discovery, reported on 28 September in Nature Astronomy1, was made using radar data from the European Space Agency’s Mars-orbiting spacecraft, called Mars Express. It follows the detection of a single subsurface lake in the same region in 2018 — which, if confirmed, would be the first body of liquid water ever detected on the red planet and a possible habitat for life. But that finding was based on just 29 observations made from 2012 to 2015, and many researchers said they needed more evidence to support the claim. The latest study used a broader data set comprising 134 observations from 2012 to 2019.

“We identified the same body of water, but we also found three other bodies of water around the main one,” says planetary scientist Elena Pettinelli at the University of Rome, who is one of the paper’s co-authors. “It’s a complex system.”

The team used a radar instrument on Mars Express called the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) to probe the planet’s southern polar region. MARSIS sends out radio waves that bounce off layers of material in the planet’s surface and subsurface. The way the signal is reflected back indicates the kind of material that is present at a particular location — rock, ice or water, for example. A similar method is used to identify subsurface glacial lakes on Earth. The team detected some areas of high reflectivity that they say indicate bodies of liquid water trapped under more than one kilometre of Martian ice.

The lakes are spread over about 75,000 square kilometres — an area roughly one-fifth the size of Germany. The largest, central lake measures 30 kilometres across, and is surrounded by 3 smaller lakes, each a few kilometres wide.

Salty lakes

On the surface of Mars, the low pressure that results from the planet’s lack of a substantial atmosphere makes liquid water impossible. But scientists have long thought that there could be water trapped under Mars’s surface, perhaps a remnant of when the planet once had seas and lakes billions of years ago. If such reservoirs exist, they could be potential habitats for Martian life. On Earth, life is able to survive in subglacial lakes in places such as Antarctica.

But the amount of salt present could pose problems. It’s thought that any underground lakes on Mars must have a reasonably high salt content for the water to remain liquid. Although this far beneath the surface there might be a small amount of heat from the interior of Mars, this alone would not be enough to melt the ice into water. “From a thermal point of view, it has to be salty,” says Pettinelli.

Lakes with a salt content that is about 5 times that of sea-water can support life, but as the concentration approaches 20 times that of sea-water, life is no longer present, says John Priscu, an environmental scientist at Montana State University in Bozeman.

“There’s not much active life in these briny pools in Antarctica,” says Priscu, whose group studies microbiology in icy environments. “They’re just pickled. And that might be the case [on Mars].”


Too salty?  Maybe.  The Great Salt Lake is very salty as is the Dead Sea and they both have life in them.   In any event, de-salination for human purposes is possible .  pl

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32 Responses to Mars has a lot of water. Who knew?

  1. JohninMK says:

    I would have thought a big problem would be getting 1km of pipe to Mars to drill a shaft down to the water.

  2. turcopolier says:

    Ah. The Limey. No. a machine will be brought for 3D printing.

  3. Two other big space stories this week. Phosphine gas was found in the Venusian atmosphere. That’s a sign of possible life living in the atmosphere rather than on the inhospitable surface. Could be bacteria or possibly something more floating around 35 miles above the surface. It was also confirmed that radiation levels on the surface of the Moon is too high for unprotected, long term human habitation. We’ll be living in the lava tubes or bringing drilling equipment with us. I’m sure drilling equipment will be going to Mars, as well.

  4. different clue says:

    In the long run ( thousands or tens of thousands of years from now) , if we want Mars to be mass-inhabitable as a “second home” planet, we will have to gather and crash enough mass into it to bring its gravity up to near where Earth’s is. And we would have to figure out how to give it a magnetic field somewhat like what Earth has, so as to shield it from the nasty life-sterilant particles that would be zapping it from the Sun.
    And if we did that, we would have to do that without de-stabilizing its orbit so that it would stay roughly where it is and not hit the Earth or the Sun or Jupiter or zip off into Deep Space.
    If we become advanced enough to master all that, we should also be advanced enough to be able to bring in an atmosphere-load of atmospheric gases down to Mars from wherever, and give Mars an Earth-analog atmosphere.


    different clue
    Increasing the mass of Mars will perturb the orbits of Earth, Moon, Venus, the Asteroid Belt and Jupiter.
    There is the possibility of loosing the one planet we have that where life has evolved, include ours.
    I think it would be more prudent to try to make the United States more comfortable place for human life; with better infrastructure, better education, and a working Post Office?
    And then may be try to makes places like the Sahara or Gobi deserts more hospitable?

  6. A.I.S. says:

    While I am all for space exploration, I think that proving we are able to terraform the Gobi or the Sahara, which, from an engineering standpoint, is much easier then doing this on Mars, is a neccessary but not sufficient precondition for terraforming mars.


    And preferably with a working Post Office – itself an innovation of the Great King – and Universal Healthcare – an innovation of Bismarck.

  8. different clue says:

    @Babak Makkinejad,
    You are correct. Right now we should focus on arresting the ongoing de-terraforming of Earth and the dismantling of survival institutions like the Post Office right now. And that means re-restoration terraforming the terra-deformed parts of Earth and then experimenting with up-terraforming the Gobi and Sahara. And up-rebuilding the institutions which are right now being subjected to deliberate and malicious teardown. Like the Post Office.
    That is why I expect any such terraforming of Mars to be thousands or tens of thousands of years from now. And the other-planets orbit perturbations you referrence may be insurmountable. In which case, up-massifying and up-gravitationising Mars should not even be attempted.
    I can think of another candidate for terra-reforming/restoring. And that would be the sterile scablands left over from strip mining for coal, most especially the mountaintop-removal version of that strip mining. Here are some images of the sterile scablands left by mountaintop removal mining.;_ylt=AwrJ7JcIQ3ZfjPwAuTFXNyoA;_ylu=Y29sbwNiZjEEcG9zAzEEdnRpZANCMjk0NF8xBHNlYwNzYw–?p=mountaintop+removal+mining+images&fr=sfp
    What if all that could be restored to carbon-eating oxygen-blowing forest growth?

  9. turcopolier says:

    different clue
    As you know I don’t agree with any of that. Your position is somewhat reminiscent of what the Spanish monarchy might have been told by an adviser who thought colonization of the New World was a waste of money.

  10. different clue says:

    I could understand disagreeing with the position that we should not try building base-colonies on Mars now. But that would only be half-way my position if building base colonies on Mars meant we could not re-terraform those parts of Earth re-beneficial to re-terraform. And de-vandalizing and re-repairing the Postal Service.
    If we could do all three at the same time, establish base-colonies on Mars and re-terraform the strip mine scablands, and repair the Postal Service, would there be a fundamental agreement with restoring the scablands and repairing the Postal Service in and of themselves?

  11. turcopolier says:

    different clue
    Earth was always mostly scablands. We have to get off this planet to survive as a species.


    different clue:
    Before doing any terraforming of Mars, I would suggest a 2-hundred year long experiment to see if plant and animal life could be sustained outside of the electro-gravitational fields close to the surface of the earth-moon system.
    Would there be a viable human foetuses possible on a Martian colony? Or a population that would thrive?
    No one knows the answers with any degree of certainty.
    Really, may be rebuild the roads in Michigan before moving to hovels on this or other planet that would make the industrial workers’ hovels of the 19-century Europe look like luxury accommodations.

  13. We need to get off this planet to assuage our thirst, need even, for exploration. As a means to survival as a species, leaving this planet is a dead end. We’ll end up whacking each other like we’ve been doing since our early days in the Sterkfontein caves. And the conditions for survival will be so precarious that the whacking will be easier and far more catastrophic than here on earth. We’re already setting up the conditions for a turf war on the Moon. On the other hand, perhaps a change in our nature could evolve among the tiny percentage of us who move off this planet.

  14. different clue says:

    @Babak Makkinejad,
    I agree with you. But I don’t think that means “never go to Mars”. We can fix some Earthside problems and do some Mars exploration at the same time. And when we are ready to do bigger scale colonization, Mars will be there when we get there.
    And solving the survival-threatening Earthside problems we now have will enhance our Survival chances long enough to Get There in a real way.

  15. JJackson says:

    I am not sure why ‘life’ always seems to look at life on Earth as its model and claim you can not have life in habitats that do not support the kind of life that has developed in our unique planetary environment. Life, of some kind, needs an information store that can replicate with some level of error to allow for evolution. On Earth the conditions were right for RNA in an aqueous solution and, once established, if any other system did develop it was probably just out performed. In a radically different environment why would a different set of molecules not be able to achieve this even if our environment would be as toxic to it as its is to us. For the first billion years of life here Stromatolites pumped a highly toxic waste product into the environment. Fortunately this was mopped up by iron dissolved in the oceans, until there was no more iron, at which point it went on to kill most of the life that had evolved. A whole new set of life forms that, could cope with the toxin, then evolved. That toxin was oxygen.

  16. turcopolier says:

    Whacking each other has not kept man from prospering. There will be war and rumors of war. the percentage of people who go forth to colonize is unimportant. A remnant must survive somewhere.

  17. turcopolier says:

    Tony L
    your apology is accepted. And a few others are re-instated as well.

  18. pl,
    What’s wrong with a remnant surviving on this world? Until our sun goes supernova or some such thing, the Earth is still offers our species the best chance of survival. Sure, civilizations will crumble. That’s inevitable. But humans can exist and even thrive in some remarkably inhospitable environments before resorting to an artificial environment needed in space or on Mars. And if humans cease to exist, maybe something far more remarkable will take our place either from this Earth or some other world.

  19. turcopolier says:

    Your evolved attitude toward life is remarkably passive and sounds like the underlying spirit of Cancel Culture.

  20. pl,
    My attitude isn’t passive. I acknowledge the mutability of life and its remarkable ability to adapt. I reject the static view of the world where everything and every creature exists in an immutable hierarchy of nature, a “scala naturae,” a world where every creature must know their place and stay in that place. No species and no society has a natural right to continue without change forever, but every species and society has an opportunity to adapt. i don’t see what cancel culture has to do with that. Cancel culture seems anything but passive.


    The Twisted Genius | 01 October 2020 at 09:28 PM
    You are projecting the Ethos of the Western Man unto the rest of mankind.

  22. Babak,
    I freely admit my beliefs stem from the ideas of Western Man, dead white men to be exact. Those ideas are also in direct opposition to the ideas of other dead white men, the midieval Christian concept of a static “scala naturae” which still guides the ethos of large swaths of Western Men.

  23. turcopolier says:

    Is this some sort of Jesuit thing derived from Teilhard de Chardin?
    Reference for the Spanish kid.

  24. pl,
    No, this is not a Jesuit thing at all. I’m familiar with the works of Teilhard and find them fascinating. However, I am skeptical about his reliance on orthogenesis. I think that idea harkens back to a hierarchy of nature. My ideas sprang from an early interest in Darwin. I built a model of the HMS Beagle as a youth which led me to read everything I could find on him, his life and his works. National Geographic introduced me to Louis B. Leakey and his discoveries about early man. Like Teilhard, I had an ardent interest in paleontology from early on. I was fortunate to take a history course called “The Century of Darwin” at RPI. The professor was an older, white-haired, disheveled tweedy type with a tremendous enthusiasm in the subject. It was perfect. To this day, it remains my favorite academic course. A question I am most interested in is when was the moment when our ancestors developed their humanity. When did they realize who they have become?

  25. turcopolier says:

    You were and are sworn to defend the Republic, not to accept its demise. Is this a Democrat talking point? We have a woman friend (yet) who waxes poetic over the coming of a new hegemon in the world.

  26. JJackson says:

    “You were and are sworn to defend the Republic, not to accept its demise.” Can one not do both at the same time?
    As TTG points out history has shown us that, so far, no species that has been ‘top dog’ has retained that position. Homo Sapiens tenure to-date has been extremely short compared to our forebearers. Likewise for the human civilisations who were all-powerful amongst their peers but faded over time. You can defend the Republic to your last full measure but still accept other powers may eclipse yours without there ever being conflict. PNAC seemed to think this could be avoided by suppressing any potential rivals ability to reach that point and institute some version of their own 1000 year Reich. This seems to be the Israeli plan too.

  27. pl,
    You and I are talking on vastly different time scales. My views on evolution are on a geologic scale, tens of thousands of years at the quickest. And it is neither a Democratic or Republican talking point. I doubt any party on this Earth can think in those time scales. On the more immediate scale of our lifetimes and this next election, I take my oath to defend the Republic quite seriously as do you, even though we interpret present conditions differently. Another four years of Trump poses a grave danger to this country, its Constitution and, yes, its soul. I see Biden, flaws and all, as the lesser weevil.

  28. turcopolier says:

    No you cannot any more than one of the Queen’s officers can equivocate over his loyalty. We give that up when we take the oath. TTG is mouthing one of the Democrat talking points of the day. I have heard it twice today from other Democrat partisans. Joe Biden’s inclination to China is affecting the whole Democratic Party.

  29. turcopolier says:

    “Another four years of Trump poses a grave danger to this country, its Constitution and, yes, its soul.” A gravely mistaken view. IMO Biden is a cheap machine politician who has sold his soul to and for his family’s corrupt money and his old man’s lust for the power he would never have even approached if the Democrats were not now so badly split and under the influence of the Marxists enemies of the US.

  30. Fred says:

    Just which parts of the Constitution has Trump violated to date?

  31. JJackson says:

    Like TTG I was thinking on longer time scales and accepting that the US has been the dominant Civilisation on the planet for much of the post WW2 period a role it took over from the British Empire which was declining and then two WW finished it off. Your officers did not have to fight ours to achieve this so there was no dereliction of duty just a decline and fall. China may inherit the role but it has been there before and is having a renaissance.

  32. different clue says:

    China may well be having a renaissance towards partial world hegemony. I would like to see America remain a successful holdout against Chinese Rule within the borders of the US itself.
    The only hope for achieving that would be a swift and sharp break with International Free Trade-ism and the restoration of a Thorough and Complete Protectionism which would allow America the space to restore what balanced industrial economic ecosystem our diminished resource base can still permit. Our trade with the One Ball One Chain Great Han Co-Prosperity Sphere should be as close to zero both ways as we can achieve.
    We must not permit ourselves to become one of China’s “overseas Tibets” the way Australia looks on track to becoming.
    We must never ever permit the building of a railroad across the Bering Strait or a tunnel underneath the Bering Strait. We must never ever permit the laying of a natural gas pipeline or huge electric transmission cables under the Bering Strait. America must remain physically air-gapped from China at that physical level to prevent a Chinese takeover by slow-overwhelm.

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