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Mars

Researchers: It's 'Unlikely' There's Water- or Ice-Saturated Layers Below InSight Mars Lander (space.com) 43

Posted by EditorDavid from the parched-planet dept.
Did Mars ever support life? One clue might be quantifying just how much ice (and other minerals) are lurking just below the planet's surface, a team of researchers argued this month. "If life exists on Mars, that is where it would be," they said in a news release this week. "There is no liquid water on the surface," but in a contrary scenario, "subsurface life would be protected from radiation."

Locating ice and minerals has another benefit too, they write in the journal Geophysical Research Letters: to "prepare for human exploration." And fortunately, there's a tool on the InSight lander (which touched down in 2018) that can help estimate the velocity of seismic waves inside the geological crust of Mars — velocities which change depending on which rock types are present, and which materials are filling pores within rocks (which could be ice, water, gas, or other mineral cements).

That's the good news. But after running computer models of applied rock physics thousands and thousands of times, the researchers believe it's unlikely that there's any layers saturated with water (or ice) in the top 300 meters (1,000 feet) of the crust of Mars. "Model results confirm that the upper 300 meters of Mars beneath InSight is most likely composed of sediments and fractured basalts."

The researchers reached a discouraging conclusion, reports Space.com "The chances of finding Martian life appear poor at in the vicinity of NASA's InSight lander." The subsurface around the landing zone — an equatorial site chosen especially for its flat terrain and good marsquake potential — appears loose and porous, with few ice grains in between gaps in the crust, researchers said.... The equatorial region where InSight is working, in theory, should be able to host subsurface water, as conditions are cold enough even there for water to freeze. But the new finding is challenging scientists' assumptions about possible ice or liquid water beneath the subsurface near InSight, whose job is to probe beneath the surface.

While images from the surface have suggested there might be sedimentary rock and lava flows beneath InSight, researchers' models have uncertainties about porosity and mineral content. InSight is helping to fill in some of those gaps, and its new data suggests that "uncemented material" largely fills in the region blow the lander. That suggests little water is present, although more data needs to be collected.

It's unclear how representative the InSight data is of the Martian subsurface in general, but more information may come courtesy of future missions. NASA is considering a Mars Life Explorer that would drill 6 feet (2 meters) below the surface to search for possible habitable conditions. Additionally, a proposed Mars Ice Mapper Mission could search for possible water reservoirs for human missions.
And of course, as the researchers point out in their announcement, "big ice sheets and frozen ground ice remain at the Martian poles."
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Researchers: It's 'Unlikely' There's Water- or Ice-Saturated Layers Below InSight Mars Lander More

Researchers: It's 'Unlikely' There's Water- or Ice-Saturated Layers Below InSight Mars Lander

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  • Water is not necessary for life (Score:5, Funny)

    by 140Mandak262Jamuna ( 970587 ) on Sunday August 14, 2022 @09:02PM (#62790072) Journal
    I remember seeing a documentary where the space ship landed in a cave in a dry arid waterless asteroid. One would think it can not support life. But what they thought as a cave was actually the guts of a very large worm, big enough for the space craft to fly in! So, yeah! water is not necessary for life.

    • I believe that was actually an episode of SpongeBob SquarePants.

    • I remember seeing a documentary where the space ship landed in a cave in a dry arid waterless asteroid.

      The odds of successfully understanding a concept with todays documentaries are approximately 3,720 to 1.

    • Depends on your definition. It's definitely needed for life as we know it. Even if you get more exotic IIRC water is extremely helpful to essential for life as we conceptualize it. If you're extracting energy from something, storing it, and using it to build bits of yourself you need a common chemical which easily picks up and drops off the stuff you're made of and the chemical energy you store.

      Alcohol could do that I suppose but water is way more common. Oil isn't reactive with nearly as wide a range of c
      • Methane is probably the most likely contender after water. Plentiful and very versatile and wouldn’t even need oxygen necessarily.
        • But methane has a very low dielectric coefficient - meaning it's not very good at interacting with polar molecules, such as organic molecules with non-carbon atoms in the carbon-carbon linked "backbone". Which is most of the interesting molecules : alcohols, amino acids, carbohydrates, fatty acids ...

          Ammonia is probably a better contender than methane. But it doesn't have to be a "pure" solvent - mixtures of ammonia, water and carbon dioxide have some very interesting eutectic points in the 0 degC to -100

          • Ammonia is considered a traditional biomarker for exoplanet atmospheres specifically because there isn’t a known abiotic path [arxiv.org] to substantial surface or atmosphere concentrations. So without another fluid or substrate to jumpstart life off the ground it would have to have evolved elsewhere to start with. The chicken and egg puzzle is simple, dinosaurs laid eggs and even if a “first chicken” were finally past some genetic line to count as a chicken it came in the egg. Therefore the lack

            • Ammonia is considered a traditional biomarker [ArXiv paper]

              The authors specifically restrict themselves to terrestrial planets, and excludes "mini-Neptunes", which are one of the most commonly observed classes of planets. I didn't restrict my consideration to the terrestrial class only. We were talking about the presence of life in the universe, not the presence of life in environments similar to Earth's. (Or at least I was - I didn't notice such a constraint in your considerations until this point.)

              I'd al

              • Of course, ammonia as a biomarker falls down when you get to planets large enough to have significant ammonia production (from N2 +H2, in the atmosphere's depths).

                Not necessarily true, there are natural sinks including many naturally occurring rocks. So maybe in a gas planet with very little actual surface, but then again it’s not clear how life could start and evolve despite convection that would subject them to massive temperature and pressure fluctuations - something generally considered incompatible with life but required for this type of ammonia production.

                On earth, life is the only reason there is substantial ammonia in the atmosphere, which is why it

                • there are natural sinks including many naturally occurring rocks.

                  Tell me, which rocks? Remembering that I am a geologist. The prime examples I can think of are ones you get by weathering metal salts (principally sulphides) in water-rich fluids. Which is not an environment under discussion.

                  something generally considered incompatible with life

                  "Life, Jim, but life as we know it." From a single solitary example. But life on Earth can exist over about a range of 1000-fold in pressure. What no life forms, on Eart

                  • You’re unnecessarily complicating things. On a planet with an atmosphere a bit denser than earth and under, also near enough to a star to have the temperatures necessary, high energy photons quickly remove ammonia by breaking it into NH2 + H or NH + H2 where it will not readily recombine again. On planets that have a massive atmosphere capable of producing ammonia, the lower levels where this happens are generally considered incompatible with life because with everything being kinetically smashed an
                    • The meter ("metre", however it's spelt in your language) is running on this on Slashdot. I moved this sideways to a blog of mine at https://wellsite-geologist.blo... [blogspot.com] a few days ago.

                      Fundamentally we are looking at different ends of telescopes that may not be pointing in the same direction (but I doubt are pointing in totally opposite directions.

                      You seem to be looking from what we currently know about life "as we know it, Jim!", towards ... Earth, science, current tech ; I'm looking from what we mean by "li

      • I would say that what's really needed is a good liquid solvent. Water is indeed a good, simple solvent that is in liquid form in the temperature regimes that allow for larger molecules needed for life to stay stable. Alcohols are similarly good solvents, but higher vapor pressure, and harder to form in large quantities. Still, they seem to me to be a good alternative for forming life (although worth noting that pure alcohol will denature many large biomolecules on Earth, so life in an alcohol pool will defi

    • Would you have the title for that? I though it came from an episode from "The Outer Limits" (1995 series) but I quickly reread the summaries and I cannot find it. Last words were "I can see it" or similar (talking about a rescue ship that is revealed to be an hallucination caused by the chemicals of by the worm guts) and last picture on screen was all the astronauts dead on the floor, except one agonizing and still hallucinating about the rescue ship.

  • The search for water on Mars is so we know if a manned mission to Mars is feasible. No water on Mars and it may be impossible to manage a trip to get humans there and back. But in addition to looking for water there's a search for anything alive there. If there are live organisms then do we send people there where they could be exposed to a potentially hazardous organism? Or where humans expose the organism to something we bring that is hazardous to them? Humans do not go anywhere without bringing all

    • Going to the sun to find out more is probably not a great idea, that's suicide. Maybe if we can keep the mission limited to the nighttime then a manned mission to the sun may be survivable.

      It'll have to be a brief stay - I hear the rents there are atrocious.

    • No doubt sending expert explorers to Mars is an interesting and worthwhile enterprise, And the dangers of the adventure have always accompanied this type of activity so that maximum care should be necessary. But to consider the entirety of the extraterrestrial as forbidden territory in light of the dangers involved to alien possibilities seems to me to somewhat ludicrous. On the other hand the eagerness to consider Mars as a refuge from our current eagerness to make Earth uninhabitable is the stuff of rathe

    • The search for water on Mars is so we know if a manned mission to Mars is feasible.

      Do you have any basis for this assertion? Like, for example, a NASA policy statement. Or a UK PPARC policy statement? Or something from any other government serious attempting to send landers to Mars?

      I bet you don't have such support for your claim. Prove me wrong by linking to a government document agreeing with you.

  • Of course there is unlikely to be water or ice sheets under the surface. Someone somewhere has to have measured it already.

    • Bad Headline (Score:5, Informative)

      by Geoffrey.landis ( 926948 ) on Sunday August 14, 2022 @09:49PM (#62790124) Homepage

      The headline misses a vital point. The correct headline is "It's 'Unlikely' There's Water- or Ice-Saturated Layers Below InSight Mars Lander, at 4.5 degrees north of the equator of Mars."

      This is critical. This isn't a finding about all of Mars; it's a finding about a spot nearly on the equator of Mars.

      At higher latitudes, yes, there's water. We know that.

    • Actually that point was one of the things the INSIGHT instrument - the seismograph, specifically - was designed explicitly to measure, by conducting a effectively long duration CDP gather to construct the velocity profile below the lander (well, strictly, the seismograph, which was deployed to the side of the lander).

      And they've just published the results of analysing the data from that instrument.

      In fact, if you cast your mind back to the 2000s, you might remember that the Phoenix lander saw [wikipedia.org], temporarily

  • Ridunculouse (Score:5, Interesting)

    by Aighearach ( 97333 ) on Sunday August 14, 2022 @09:49PM (#62790122)

    Did Mars ever support life?

    That has nothing to do with any of the science being discussed. Of course Mars supported life; it was warmer and wetter while there was life on Earth, and there are lots of rocks exchanged. So Mars had to have supported some life, at times.

    The interesting questions have more nuance; did Mars support an ecosystem? Did an ecosystem originate on Mars? Did Mars support life prior to Earth doing so? Was Earth life seeded by Mars? How long did Mars support life; how far did it evolve? Etc., etc. Those are the types of questions that nerds ask.

    • If we did find life, a genetic analysis alone (provided it even has dna given an alternate evolutionary path early on) would answer many of these questions.

      • It's a lot more likely we'll find a chemical signature that we won't really understand for decades or centuries, during which time we'll argue and call each names over it.

        • It's a lot more likely we'll find a chemical signature that we won't really understand for decades or centuries, during which time we'll argue and call each names over it.

          We will not argue, you moron!

          Put down the pitchforks. It was meant as a confirming joke. I'm sad I have to add this bit, but everybody's so sensitive these days. Sigh.

    • Re:Ridunculouse (Score:4, Insightful)

      by UnknowingFool ( 672806 ) on Monday August 15, 2022 @12:56AM (#62790306)

      That has nothing to do with any of the science being discussed. Of course Mars supported life; it was warmer and wetter while there was life on Earth, and there are lots of rocks exchanged. So Mars had to have supported some life, at times.

      There's a difference between Mars could have supported life and there was life on Mars. So far there has not been any evidence there was life.

    • Of course Mars supported life; it was warmer and wetter while there was life on Earth, and there are lots of rocks exchanged. So Mars had to have supported some life, at times.

      That's a lot of wild theories you're presenting as fact. The whole reason we're out there testing is that we don't know.

    • Re: (Score:2)

      by kbahey ( 102895 )

      ... did Mars support an ecosystem?
      Did an ecosystem originate on Mars?
      Did Mars support life prior to Earth doing so?
      Was Earth life seeded by Mars?
      How long did Mars support life;
      how far did it evolve?

      Exactly ...

      And add the following profound questions too:

      - Was life on Earth seeded from Mars, or was Mars seeded by life from Earth?
      - Or, did life evolve independently on each of those planets?

      My personal view is that simple unicellular microbial life is ubiquitous in the universe, but there is a higher barrier

      • Indeed, panspermia seems the most obvious, simple answer to where life comes from.

        However, demonstrating that scientifically has a lot of in-between steps that have to be completed first, since we lack any sort of "space exploration" program. Everything from astronomy (looking at space) to building commercial moon bases gets described as being part of "space exploration," but meanwhile, we do almost no actual exploration. We're taking baby steps to explore Mars, as in the context of this story, and we're ta

        • Re: (Score:2)

          by kbahey ( 102895 )

          Panspermia is not really a solution. It just pushes the problem of the origin of life elsewhere.

          What I leaning towards is the hypothesis that independent origin simple life (single celled bacteria/archea like) is ubiquitous in the universe, and arises fairly quickly after a planet cools enough and has the necessary ingredients for it.

          Unfortunately, we will not know any time soon what the whole story is ...
          Mars and Earth are very close together, and life could have been cross seeded from one to the other.

          But

  • They just never send probes there because it tends to be in regions with younger terrain. Which, from the surreal POV of planetary science, makes places on Mars with a lot of H2O somehow less "scientifically interesting" than ones that preserve eons-old geography.

  • We all know how to produce water on Mars.

    Mark Watney has demonstrated that carefully burning hydrazine in a lab will give you all the water you need, and maybe some burnt eyebrows. Add in some human "manure", and you can even start a potato farm.

    Just make sure you bring a large variety of music. Disco goes stale very quickly.

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