back to article Mars was a WET mistress: Curiosity probes once-moist bottom

NASA's nuclear-powered Curiosity rover has found evidence the three-mile-high Mount Sharp on Mars was once under a large lake. Mount Sharp lake A few billion years earlier and Curiosity would have needed water wings "We are making headway in solving the mystery of Mount Sharp," said Curiosity Project Scientist John …

  1. Grikath
    Pint

    well , there you have it....

    If there ever was a site we need to send a retrieval team to for rock samples this would be it...

    On earth a formation like this would make an archeologist cry tears of joy. On Mars this stuff may well contain the precious, prreciousss evidence telling us whether or not life once existed there , even if only on a microscopic level.

    For me, this is one of the most stunning pictures the Rovers sent back. There's Stuff out there, and we have an actual chance getting at it.

    1. Beachrider

      Isn't it GREAT that so much will be known...

      These kinds of rover missions are meant to establish what-we-need to do to make our 'move' on Mars?

    2. P. Lee

      Re: well , there you have it....

      I'm still not sure about the reason for the obsession with life elsewhere.

      There's plenty of it here.

      If we found it, what would it prove? How would it change anything?

      1. Grikath

        Re: well , there you have it.... @ P.Lee

        Besides ending a couple of centuries of debate on Matters , giving a strong indication "life" could be the norm, rather than the exception in the universe given favourable conditions, and some other minor stuff in the realms of pure science which obviously wouldn't interest you at all.. ?

        nothing to see here, move along..

        1. Anonymous Coward
          Anonymous Coward

          Re: well , there you have it.... @ P.Lee

          >If we found [life on mars], what would it prove? How would it change anything?

          For sure, there is a very strong case for putting almost all our resources into the means of detecting, tracking and diverting/destroying asteroids. After we, as a species, are confident that we won't be suddenly sent back to a pre-agriculture (or pre-vertebrate, if it's a ig enough rock) ) society , we can cheerfully allow our engineers to peruse other areas, such as seeking life on Mars.

          We know that big rocks regularly hit planets and moons. We know that the consequences can be devastating. We know that it is just an engineering problem, and so can be solved.

          So, compared to that, how important can Mars be, to our species?

          Well, we're a strange species.

          Pople did fear that we would wipe ourselves out with nuclear weapons. It is no coincidence that most of the space-exploring milestones were achieved during this time. As nation-state willy-waving goes, there are worsse trhings that sending robots to planets.

          Who knows, maybe enough people will just think it's really fucking cool.

          Finding evdence of life on Mars - and thus have another variable to stick into Drake Equation -

        2. Anonymous Coward
          Meh

          Re: well , there you have it.... @ P.Lee

          @ Grikath

          Meh, if there are really Martians they will just end up needing our women, or siphoning off our blood to inject into their anemic bodies. All things considered, it doesn't sound like a good deal to my ears....

      2. Mark 85

        Re: well , there you have it....

        Quite a bit really and the result of finding won't be pretty. How about all the major religions will now collapse or react violently to those "disbelievers" who tell this lie? Much like there are some who disbelieve we've ever stepped foot on the moon, instead of a fringe movement, this would probably be pretty much world wide.

        We are a nasty life-form that doesn't like it's fairy tales to be found un-true.

        1. adnim

          @Mark...Re: well , there you have it....

          I don't expect such a discovery to have a great impact on religion. Reality and evidence based rationalism doesn't rate very high in most belief systems. A verse from any of the scriptures that underpin modern religions will just be re-interpreted to take account of the discovery.

          1. JDX Gold badge

            Re: @Mark...well , there you have it....

            I'm not aware of major religions who teach life only exists on one planet. Just as the bible/torah/koran don't explain quantum mechanics or _how_ life appeared (except when read in a very literal sense which already contradicts most of what science teaches), they simply don't discuss such matters because nobody had the concept there even WERE other worlds, or really knew what a world WAS.

            The bible for one, clearly says the universe is part of creation, not just earth. It says God made the universe, and then God made life on Earth.

            The existence of life itself doesn't challenge anything anyway. Only the existence of sentient life - the major religions focus on humanity and count other life as less important - cats don't have to accept Jesus, etc. The big question would, I think, be how intelligent life was folded into that. Some would probably argue only humans 'count' and other species are like animals - they live, they die, that's it. Others would have to figure out how a seemingly Earth-centric religion - why did Jesus come to our planet - applies to other species. The Speaker for the Dead books by Orson Scott Card tackle this to some degree.

            And of course, other sentient species may well have their own religions. The notion that only humans have religion is falling into the same trap claiming humans are 'special'. The fact Earth has many contradictory religions hasn't caused us to say "well that's clearly crap" so finding other species have their own religions wouldn't either. Some atheist ideal that finding other life will cause the whole house of cards to collapse is just fanciful naivety which shows as little understanding of people as the crazy religious folk.

            1. Trevor_Pott Gold badge

              Re: @Mark...well , there you have it....

              Alien religions won't likely say "humans are special", though. And I doubt they'll say "control women's vaginas" or "adhere to the authority of the leader of this human cult".

              So they're blasphemers.

              1. chris lively

                Re: @Mark...well , there you have it....

                So, basically, when we actually do find aliens then it will be time to bring out the Inquisition in order to purge them of their heretical beliefs?

                1. Trevor_Pott Gold badge

                  Re: @Mark...well , there you have it....

                  No, I think we'll have a bunch of people on Earth who try to kill off everyone else on earth who believes the aliens exist, because they won't accept the science, and find those that believe in aliens to be heathens. The question is: will those be a lot of people, or only a few? It's the next couple of generations that will tell the tale, as (thank $deity), we're starting to really get people to move away from being literalists.

                  The fewer literalists, the lower the chance for massive social upheaval.

          2. Uffish

            Re: @Mark...well , there you have it....

            From basic general knowlege I understand that the Muslim religion expressly expects to find life 'out there' and I don't think the Roman Catholic church would be in any way perturbed by finding evidence of 'independant-of-earth' life. I don't know nuffink about other religions but would be surprised if they had much of a position on the subject.

            I'm shutting up now because people who constantly air their views on religion are a bore.

        2. James Micallef Silver badge

          Re: well , there you have it....

          "all the major religions will now collapse or react violently to those "disbelievers" who tell this lie?"

          Knowing a bit about human psychology and the extreme capacity for cognitive dissonance, I would go for a third option - the religions would just twist some arcane official doctrine and carry on regardless.

          [Edit] - adnim got there first! have an upvote

          1. Anonymous Coward
            Anonymous Coward

            Re: well , there you have it....

            Roman Catholics have already discussed their opinion on extraterrestrial life, at length, and the discussions have been going on for hundreds of years. Google for it.

            Theologians are a bit weird, but they're not stupid.

        3. Gary Bickford

          Re: well , there you have it....

          I don't think finding exo-life will be a problem for most religions or religionists. There are a very few extremists (with highly skewed views of their own religion) who will have a problem, but the question of exo-life has been discussed quite a bit in various religious communities for a long time. I just saw a pretty good analysis on just this topic. Some religions actually believe in exo-life - Mormon, Scientology (if that's a religion at all, but we won't go there), a couple of others that I forget. IIRC the only problem within mainstream Christianity would be the question of whether and how Jesus' redemption applies.

          James Blish's "A Case of Conscience" (http://en.wikipedia.org/wiki/A_Case_of_Conscience) in 1958 , which explored the question of the doctrine of Original Sin and redemption upon finding a "sinless" alien society.

          And I don't think we're any nastier than most others. What we do is not different in kind than almost every other life form - look at how most wasps use other insects as zombie hosts for their offspring. Termites have an impact on their local ecosystem that is pretty similar to our impact, given the difference in scale - there's even a completely different ecosystem inside a termite mound. The best way to look at us is as an tool of Earth Life, with the capability to create "spores" that carry Earth Life to other places. This is pretty much how fungi propagate. Everywhere we go in the Universe, we'll be bringing our ecosystem with us, propagating it as we go. That's successful Life.

        4. Mark 85

          Re: well , there you have it....

          First off, we're a rather well-thought, and intelligent bunch here. We rationalize and even think about things and opinions. So....

          While I agree with the general sentiment that the "home offices" and basis of the major religions won't have a problem with finding life elsewhere, it's the "down in the trenches" I think will have the issue. Look at the way the Bible was justified for horrible things. A rather innocuous one, being the burning of the tablets on Easter Island. Or the various warring, not even nice to each other much less outsiders, fundamentalists in the Muslim world. Or how about here in the States. If NASA finds life, I expect the head of the Space Committee in Congress will raise hell about cutting off the funding since the Bible tells him that the Universe is only 6000 years old and yada-yada. He's not even one of the more radical "Christians". The list can go on, but that's the thought process.

          It's the actions of the factions and those who follow blindly the teachings of their local shaman that I think will be cause the "not pretty" part of my original post.

      3. Trevor_Pott Gold badge

        Re: well , there you have it....

        "If we found it, what would it prove?"

        It's not about what it would prove so much as what it would disprove. If there is life that is not on Earth, then Earth isn't special, and the case for god or gods becomes much, much more difficult. If life exists (or existed) "out there", then it is a victory for rationalism and critical thinking and an important defeat for faith and Terracentrism.

        If your evidence for god is nothing more than an ever-receding pocket of scientific ignorance then the small you can make that pocket of ignorance the fewer people will cling irrationally to faith. If nothing else is achieved from the Mars explorations except that, we will have nonetheless accomplished something mighty.

        1. spinynorman

          Re: well , there you have it....

          Any truly spiritual person does not attach the notion of God solely to the human race - that person attaches the notion of God to everything! So actually finding evidence of any other form of life does nothing to detract or reduce the notion of God to a spiritual person - it serves to enhance the respect for the whole of creation. It certainly does not disprove the existence of something that is greater than what most humans appear to accept is their own physical existence. It is clear that you are obviously not a spiritual person, so I wouldn't expect you to understand or accept this. Perhaps one day you will have cause to open your mind.

          1. Trevor_Pott Gold badge

            Re: well , there you have it....

            s/"Any truly spiritual person"/No True Scotsman

            There are plenty of "spiritual people" that would have you labelled a blasphemer for what you just said. $_text is the literally truth, and anything else is lies. Or didn't you know that?

            But, oh, you aren't a fundamentalist, eh? Texts are mooshy and open to interpretation. So then it's all about how you feel about things. Truthiness has more value than truth.

            Of course, the part where you are just a sack of chemicals and I can change how you feel by putting the right chemicals into you won't open your mind to the truth of science, will it? Thought not.

            My mind is plenty open, sirrah. And I need no more majesty than the universe itself. It's plenty mind boggling as it is, no "higher power" required. In the meantime and between time, the ability to see off some of the "$text is the literal truth" whackos is worth a thousand times the current expenditure on space.

            Sadly, I have no idea how to go about enlightening the truthiness brigade, but that won't stop me from seeking a means to that end.

        2. JDX Gold badge

          @trevor

          It's not about what it would prove so much as what it would disprove. If there is life that is not on Earth, then Earth isn't special, and the case for god or gods becomes much, much more difficult. If life exists (or existed) "out there", then it is a victory for rationalism and critical thinking and an important defeat for faith and Terracentrism.

          Considering conventional teachings are that the whole universe is God's creation, the existence of other life doesn't make anything more difficult, except believing is specific religions whose teachings dispute this. God/gods either exist or not, regardless of the arguments we make (unless you follow Discworld theology!) Your arguments are very heavily biased by the outcome you already expect, just as religious people's arguments are typically coloured by what they believe.

          If your evidence for god is nothing more than an ever-receding pocket of scientific ignorance then the small you can make that pocket of ignorance the fewer people will cling irrationally to faith. If nothing else is achieved from the Mars explorations except that, we will have nonetheless accomplished something mighty.

          The "God of the Gaps" angle is not the basis of informed faith. It is an ignorant atheist who clings to this understanding of faith as the only way anyone could be genuinely religious.

          1. Trevor_Pott Gold badge

            Re: @trevor

            "Informed faith" is an oxymoron. By definition, faith is belief where knowledge isn't possible.

            That said, methinks you presume a lot from other "people of faith". Just because you have manged some high level of cognitive dissonance in which you compartmentalize faith and an understanding of at least basic science doesn't mean the majority do.

            The number of people out there who honestly believe in the god of the gaps - and use it regularly when attempting to convince atheists their faith is true - is huge. There are far - far - more people out there who reject science, reject the idea that things like "life on other planets" could exist than you seem to be willing to accept.

            Maybe you got "lucky" and ended up with a shaman and congregation that actually believe some variant of $_religion that is compatible with $_Y_percent of modern scientific understanding. Congrats. That's pretty cool, in a way, but it isn't the "mainstream" experience.

            If anything, those sorts of questions and discussions are carefully avoided by the "mainstream" shamans. They focus on $_mandmans_text and espouse their interpretation. But for billions of people on this planet religion is taught far closer to "$_madmans_text is the literal truth". And there's where it all goes horribly wrong.

            If you're a harmless religious type who is capable of somehow reconciling modern science with irrational belief in the unknowable, then to put it bluntly, it doesn't matte what you believe, or why. You are highly unlikely to be a threat.

            But the $_mandmans_text literalists? They are threats. Each and every one. Anything that can be done to get people to walk away from that belief system is worth doing. The money spent becomes justified quite quickly when the ranks of the literalists is thinned.

            Maybe the move from being a literalist to a science/faith cognitive dissonance type. Cool. Groovy. I don't care. Once they're not $_mandmans_text literalists their chances of being a threat are spectacularly reduced.

            So what's important here isn't proving "god doesn't exist" to the cognitive dissonance types. They're not relevant. What matters is having one more tool to use in attempting to save those who have been sucked in to $_mandmans_text literalism.

            We'll work on the cognitive dissonance types in future generations, once we've dealt with those who are actual threats.

      4. Gary Bickford

        Re: well , there you have it....

        I tend to agree that there appears to be an overemphasis. But ...

        - I can excuse the scientists + media: the fascination with exo-life seems to get good public response, which translates to more funding for space-related research, which is IMHO a Good Thing. I think it's even achieved a bit of 'reality show' interest - "The Ongoing Quest to Discover Whether We Are Alone".

        - There are actually good reasons (both scientific and practical) to know if there is life of any kind elsewhere, and whether it has the same DNA history. And I'll be amused at the collective consternation if we discover living or potentially-living organisms on Mars, as the conflict between the desires for protection and study arises.

        - Again from a practical point of view, the exo-life question has big potential effects on our plans to establish human residence off Earth, which IMHO is essential to our society both short and long term.

    3. aberglas

      Re: well , there you have it....

      By "send a retrieval" team you imply of people. What we actually need to do is send another robot that can dig deeper and do a bit more analysis. It could possibly send back a sample although there would be little point if the sample could be fully analyzed on Mars. We live in an information age, that is all that we need.

      Astronauts are obsolete technology. If the billions wasted on the space station and the shuttle had been spent on probes and space telescopes we would know a lot more than we know now. As it is, the Webb telescope gets delayed...

      1. Wzrd1 Silver badge

        Re: well , there you have it....

        'Astronauts are obsolete technology.'

        Not really, we still occasionally need someone to turn a wrench.

        Ideally, we would need to send a nice chunk of a university, with full labs, to Mars. Teams could range about and collect specimens from all over the planet (along with the robots that do a reasonable job of it).

        But, ideally, we'd have reliable supply trains to and from Earth, launch costs would be near zero and equipment would be intrinsically safe.

        The reality of it is, we have none of that ideal, only what we currently have at our level of technology. With our current technology, we'd likely lose those astronauts to radiation, illness or accident.

      2. cray74

        Re: well , there you have it....

        "Astronauts are obsolete technology. If the billions wasted on the space station and the shuttle had been spent on probes and..."

        My understanding is that a trained geologist in a space suit can accomplish about as much science in an hour what your typical high-end robotic rover does in a year. There's just something so convenient and fast about being able to cross a few meters in a couple of hops (without requiring a week of debate by the navigational steering committee), ID and select rocks for inspection in seconds (without requiring a week of debate by the science committee), and cutting out all those interminable hours of accumulated speed-of-light communication delays to see if everything's going well. Apollo 16 and 17 explored areas in hours (3.5 and 4.5 hrs) that it took the Opportunity 10 years to cover.

        Probes can accomplish a lot and they're nice when they're the only option affordable on your budget, but we're not necessarily "learning a lot more" than if we had human boots on the ground.

      3. Gary Bickford

        Re: well , there you have it....

        Astronauts, if obsolete, are only obsolete in the context of robotic exploration and some very basic science. (But Buzz Aldrin noted that all of the research findings of all of the Mars rovers and landers over the last 30 years could have been accomplished in a week or two by human astronauts landing on the surface.) There are many, many science experiments that could be done on the surface of other bodies by humans that are essentially impossible to do robotically.

        There is also the element of accidental discovery. If the ISS were not 'humanized', many of the things we have learned about space and physics in microgravity would not have been observed or discovered. A rather mundane but amusing example is how liquids behave in microgravity - see Col. Hadfield's video of how water wraps around objects including his hand.

        But more important, for those of us who are convinced that humans, and Earth life in general, must be propagated across the Solar System and beyond, astronauts are the whole point. Scientific research stations are a first step. Every bit of scientific and technical advance brings human space habitation that much closer.

        There are also good, economic reasons, if/when space industry develops, it will gradually become cheaper to have humans living in space to fix and run things than to do it all completely robotically in space. This is nontrivial. A recent article (2012?) by a prominent economist showed that space industrial development had the potential of improving the standard of living of everyone on Earth by a factor of 10. In my view, there are four non-science aspects: our existing and expanding Earth Observation systems, tracking weather and other things are now saving thousands if not millions of lives every year, and improving our drive to work; things like Space Solar Power have the potential of eliminating all of our coal, nuclear, oil, and gas-fired electrical power plants; a wide range of new technologies that will only be manufacturable or operable in high vacuum and/or microgravity will drive yet another technological leap forward; and finally space "mining" - extraction and retrieval of materials that are hard to find on Earth, such as platinum (platinum would be a widely used industrial metal if the price weren't so high - extracting from asteroids has the potential of cutting the cost by a factor of more than 100.)

      4. Cynic_999

        Re: well , there you have it....

        Robots can be made reasonably capable of investigating the known unknowns. They are not however particularly good at even discovering the unknown unknowns. A human with a piece of rock under a microscope may well see some anomaly that 1000 robots would miss because they haven't been programmed to look for such a thing.

    4. Uffish
      Headmaster

      Re: archeologist

      Perhaps archeologist is a bit optimistic? Let's hope a paleontologist will be needed.

  2. Eddy Ito
    Pint

    Liquid water would not only require a higher temperature but also a higher atmospheric pressure. Without saying it absolutely wasn't water, I do think it would be easier to have had lakes of some other fluid like methane much the same as Titan has which would create similar sedimentary layers. Hopefully India's Mars Orbiter Mission will give some answers in the short term and the ExoMars TGO mission will provide more detail in the future. Whatever the answer is, it has that familiar feeling I had when a much younger me would study the news of earlier missions to the Moon.

    1. Grikath

      ummm you do know that even now Mars is too warm to sport liquid methane in any quantity, let alone a while ago?

      *hands Eddy Ito a Physics For Dummies booklet. With pictures.

      1. Eddy Ito

        My aren't we acerbic today? It was an example, perhaps you've heard of them. Please note I didn't say it had to be methane. Also note I didn't say Mars was Titan. The temperature of liquid phases also depends on pressure not temperature alone and, as I'm neither a Marsologist nor a Titanologist, I don't know their habitat off the top of my head neither now nor half a million years ago as you obviously do. Then again, the temperature of Mars isn't really that high on my give a shite list.

        1. Wzrd1 Silver badge

          "Then again, the temperature of Mars isn't really that high on my give a shite list."

          OK, Mars is really cold. Frostbite to shivering cold, assuming standard atmospheric pressure, which it is not, the atmospheric pressure on Mars is low enough to kill you quickly. But, it's high enough that minor assistive methods would be required to ensure human survival, compared to deep space, interplanetary space or on the moon.

          Titan is cold, as in colder than a witches tit, cold enough to give the frostbite on the witches tit frostbite, while the witch froze to death quickly.

          A comparison for Titan is, well, Pluto. A bit further out, oxygen freezes and falls as snow, if there was an atmosphere on Pluto to speak of. More importantly, stick Titan out near Pluto's orbit, hell, follow Pluto past the L4 L5 points, watch the moon freeze hard quickly. Tidal forces warm that moon above freezing. Hell, put it away from the planet's orbit (see Lagrange points), the moon would freeze solid there as well. Tidal forces add heat to that body, but you'd freeze solid quickly there.

          1. Eddy Ito

            "colder than a witches tit"

            I dated a witch once, her tits weren't especially cold and were rather warm actually. Well except during those outdoor Yule rituals but I guess that's to be expected.

      2. Wzrd1 Silver badge

        Well, I can think of a few other things that could have caused it, other than methane.

        Hydroxic acid, dihydrogen monoxide, hydrogen hydroxide, μ-Oxido dihydrogen.

        Now, it we were speaking of Mercury, I could think of bismuth alloying as the sun began heating. But, that's a cat of a different species, let alone color (colour for a minority of the world, if I recall native English speaker number correctly). ;)

        For the few who don't get my first paragraph, they're all a short list of names for water. When I was young, water was also referred to as "the universal solvent". Something of an interesting notion at that time.

        1. Shrimpling

          Hydroxic acid, dihydrogen monoxide, hydrogen hydroxide, μ-Oxido dihydrogen.

          I wouldn't have included the last paragraph, but have an up vote anyway.

        2. Uffish

          Oxidane

          Good joke, and a good point but you tripped up on the 'color/colour' bit. Most people in the world write 'colour'.

        3. deadlockvictim

          color | colour (bloody French)

          Wzrd1» let alone color (colour for a minority of the world, if I recall native English speaker number correctly). ;)

          If you go by the numbers of native speakers, that is, people with some flavour of English as their mother tongue, then you are surely (Shirley?) correct.

          However, if one takes into consideration the number of people who have English as one of their languages, then I think that the vast majority of English speakers on the Indian subcontinent would make that minority a majority.

    2. Wzrd1 Silver badge

      "Liquid water would not only require a higher temperature but also a higher atmospheric pressure."

      It's generally theorized that Mars had a rather dense atmosphere, which was lost when the core froze and Mars lost its magnetic field.

      As for methane, not a chance. One would need a denser atmosphere *and* it to be a lot colder. Methane is the primary ingredient of natural gas, it doesn't freeze or turn to liquid under the North Sea, it doesn't liquify on Antarctica, it'd still be a gas on Mars, even if Mars had Earth's atmosphere.

      There's evidence that Earth had a much denser atmosphere, but lost a fair amount to space and a fair amount to weathering of rock. Weather, in turn, releases some of the trapped gases into the atmosphere and our magnetic field keeps losses to a minimum, as it keeps the solar wind away from our atmosphere (OK, don't jump on that one, folks, simplifying it down, the solar wind is lessened, but largely deflects to two regions on Earth, following magnetic field lines (and I know, that's still simplified)).

      Now, when we get into planet sized dynamo action (multiple, actually) or solar ones, things get *really* tangled. Literally. The field lines average for a total north and south, but it's due to a larger number being tangled in a certain configuration. That breaks down and a reversal can occur.

      Simulations of the Earth's magnetic fields that show the larger field lines look like a ball of string that threw up on itself, then tried to swallow itself partially. While the laws involved are well understood, the interactions are mathematically poorly understood for the entire grand data set.

    3. Dan Paul

      Mars changed.....

      What happened was that Mars changed from a planet with liquid water and appreciable atmosphere to one that does not. That's all we know for sure.

      There are too many possibilities to postulate why, but an asteroid strike could certainly cause this. Various scenarios show that an asteroid strike could literally vaporize all the liquid water from any planets surface and along with it, the planets atmosphere could be blown into space.

      There are many asteroids near Mars and the gravitational influences from Jupiter and Saturn have regularly caused issues, possibly tearing a proto-planet apart to create the asteroid belt.

      It would have to be a lot colder than Mars is or have a much higher atmospheric pressure than the gravity on Mars could create to have liquid methane or methane ice.

  3. Turtle

    Rocks.

    "Sedimentary rocks at Mount Sharp" that accompanies the article is an exceptionally beautiful picture. (Not sure if it has been "colorized" or if that is what the human eye would see if it were there in real life, though.)

    I wonder how sure they are that the sediments could only have been formed by liquid water and not some other liquid.

    1. Grikath

      Re: Rocks.

      which other liquid would that be then, pray tell? You may assume temperature and atmospheric pressure to be equivalent to current temperate climate on earth with about half the atmospheric pressure. ( or a nice spring day halfway up the Alps/Rockies if you want the romantic picture)

      1. Eddy Ito

        Re: Rocks.

        Seriously Grikath, I don't know where you get that kind of bullshit but someone has to call you on it. The Alps or Rockies don't have a daily temperature fluctuation of 180 °F between day and night on a nice spring day. Sure it gets up to 35 °C/ 95 °F on Mars but that swing means it's going to get real damn cold. Granted, that's on the equator but it isn't like the poles are a pleasant day at the beach either. As for pressure, you're a bit clueless if you think 7.5 millibars is the pressure halfway up. Unless of course you think roughly 43 km (140,000 ft) is halfway up and the folks who claim Everest's 8.8 km is the highest peak on the planet are way off.

        P.S. you can have your book back as you might be able to trade it for a clue.

        1. Wzrd1 Silver badge

          Re: Rocks.

          "P.S. you can have your book back as you might be able to trade it for a clue."

          First lesson, science has a clue. Mars had a robust atmosphere in the past, back when it still held a magnetic field to deflect solar wind erosion of that atmosphere. Indeed, Earth loses hydrogen from water each and every day, courtesy of remnants of that solar wind reaching us past our magnetic bubble.

          You further fail by considering the day/night conditions on *present Mars* and ignore the past, when an atmosphere would retain heat.

          I'll give you the Everest temperature and conditions, conditions halfway up are... Challenging on a physiological level, rising higher risks significant medical hazards of a lethal variety.

          BTW, it's rather well evidenced that Earth had a substantially "heavier" atmosphere, which eventually had mixed reductions of rock and soil. First, there was the oxidation era, when photosynthesis caused free oxygen to flow in increasing amounts. A *lot* got trapped in various rocks at that time, reducing gases in the atmosphere. Add in the losses I mentioned earlier, you get the past and present. Weathering releases oxygen and nitrogen, soil upturn for farming releases more nitrogen. Fertilizing a field increases nitrogen. Still, not a biggie, that era is recent, science has yet to notice a global change and is unlikely to do so in my lifetime.

          1. Anonymous Coward
            Anonymous Coward

            Re: Rocks.

            Mars had a robust atmosphere in the past

            god created earth

            moon is cream cheese

            all summised, not known for certain until proven in endlessly repeatable experiments

            science is about facts, it's also about theories based on our own frame of reference, what happens on Earth

            1. Trevor_Pott Gold badge

              Re: Rocks.

              We don't need to observe a thing directly in order to know it occurred. Evidence occurs in multiple forms, and where it can be tested empirically gives science a window into the unobservable.

              For example, there are plenty of geochemical signatures that - to our current knowledge at least - can only occur with Mars having had a thicker atmosphere. Perhaps more to the point, when we replicate relevant conditions in a lab (and Earth itself is one hell of a lab, never forget,) we see identical (or near enough as makes no difference) geochemical signatures.

              That moves the balance of probability from "Mars was always as you see it now" to "Mars had a large atmosphere". Evidence then starts stacking up and eventually the "thick atmosphere hypothesis" moves from hypothesis to Theory. This means that we no longer need to prove that it occurred; there is so much evidence that it did we can simply take it for granted.

              Instead, if you want to advance an alternate hypothesis - for example, the hypothesis that Mars was always as you see it now - you need to do the work. You need to not only demonstrate how this could be true, but explain away all the supporting evidence for the thick Martian atmosphere theory.

              That's how science works.

              How science doesn't work is that every time something comes along that you disagree with because it makes you uncomfortable you get to derail the conversation by demanding that every single element be explained to you down to base principles. Once something has proven itself enough to be a Theory then the onus isn't on scientists to explain everything to you, but on you to explain how your alternate view of the world fits with the evidence accepted by the scientific community.

              In other words: yes Mars had a thick atmosphere. And the burden of proof is on you as the one challenging science for which there is strong evidence to provide not only new evidence for alternate claims, but an explanation for all extant evidence.

              Now, if you have an explanation for an alternate hypothesis that matches all extant evidence, I'm entirely open to discussion. Otherwise, you're aught but a troll.

              1. Turtle

                @Trevor_Pott - Questions And Statements, Valid And Otherwise

                Look at my original question: "I wonder how sure they are that the sediments could only have been formed by liquid water and not some other liquid."

                Now let's look at your post. First you state "there are plenty of geochemical signatures that - to our current knowledge at least - can only occur with Mars having had a thicker atmosphere." And then - just a few words later - you state "This means that we no longer need to prove that it occurred; there is so much evidence that it did we can simply take it for granted.

                So in the span of a few short words you've managed to go from the correct idea that scientific theories are provisional and subject to change (in consequence of the acquisition of better data, different interpretations of the data or of the pre-existing theories on which the theory under discussion is built, or simply in consequence of someone having newer and maybe better ideas), to the completely erroneous idea that science has arrived at something which you seem to think is very, very close to an incontrovertible truth.

                That you think that we have arrived at a state where we are able to reveal the ultimate truth in this matter is laughable; I would be very surprised if any scientist actually involved in these matters would take the same view.

                What you seem to be unaware of, is that a theory built on a series of high-probability statements becomes a lower-probability theory the more higher-probability statements it includes. Here: calculate the probability of a theory being correct if it is based on FIVE statements each with a 90% probability of being correct. Hint: the probability of five statements, each having a 90% probability of being true, all being true is a somewhat underwhelming 59%.

                By the way, that's one of the reasons why astrophysicists, astrobiologists, xenobiologists, and their ilk, want more scientific space missions: because the certitude that you have is something that they don't have. You seem to think that "our current knowledge" has enabled us to arrive at The Truth.

                To sum up: your vacuous post and pompous disquisition on how science operates (in your limited understanding) really don't answer the question of "how sure they are that the sediments could only have been formed by liquid water and not some other liquid" Some essentially empty babble about "geochemical signatures" and "evidence stacking up" is empty handwaving. And although the earth might indeed be "one hell of a lab" it is not "one hell of a lab" for absolutely whatever needs to be found out - and it might not all that effective for finding out the natural history of Mars. It's possible that extrapolating from the earth to Mars might actually mislead us. This is what needs to be actually be discovered, not merely surmised.

                Furthermore, asking how sure scientists really are of their theories is not - as you seem to think - some form of lese majesty against science. What is actually is, is a very valid question.

                1. Trevor_Pott Gold badge

                  Re: @Trevor_Pott - Questions And Statements, Valid And Otherwise

                  "So in the span of a few short words you've managed to go from the correct idea that scientific theories are provisional and subject to change (in consequence of the acquisition of better data, different interpretations of the data or of the pre-existing theories on which the theory under discussion is built, or simply in consequence of someone having newer and maybe better ideas), to the completely erroneous idea that science has arrived at something which you seem to think is very, very close to an incontrovertible truth."

                  No, I think what's key here is that you seem to believe that a very - very - small possibility that the current theory is false means that, somehow, it is almost inevitable that this will be proven wrong.

                  I am not taking any offence at all to your asking what is the current state of knowledge. What i took offence to was your request that things be know "beyond a doubt". KNowing anything "beyond a doubt" is utter horseshit, yet that seems to be the standard you require before you believe something.

                  If anyone is "pompous" here, it's you.

                  You clearly have an agenda and are determined to see others agree with it, though you're attempting to wrap it up in inquisitiveness.

                  Contrary to your bogus assertions, I do not believe that we have arrived at "The Truth" at all, because I don't share your irrational requirement for knowledge to be "beyond a doubt". I am, however, entirely content to look at the evidence, say "the possibility that we're wrong about this is irrelevantly small" and move on to building on that knowledge to ask newer questions and learn more things.

                  You're like a creationist screaming that we shouldn't set about working on new isotopic dating methods because we haven't proven "beyond a doubt" that the Earth isn't only 6000 years old. With perhaps a handful of exceptions, the entire scientific community is perfectly happy with the evidence that the Earth is way the hell older than 6000 years, and is ready to put it's time and effort into getting more accurate information about just how old, and the details of it's evolution.

                  Similarly, here we are with a scientific community that is pretty chill with the idea that Mars has a wet past, but you're demanding "beyond a doubt" evidence. Most scientists aren't trying to prove Mars had a wet past any more, they accept that it had one. They're not trying to find out how wet, and over what periods, and what the conditions were in those waters, how long did it last, etc?

                  So, do I find your "stop science, I don't think we're sure beyond a doubt" to be utter fucking horseshit? Absolutely. Do I accept that we've got this "wet Mars" thing taped enough to stop working on if Mars was wet and start working on how wet Mars was? Again: absolutely.

                  Search hard enough, and you'll find someone with a science degree who will claim the Earth must be younger than 6000 years. If any when they can explain away all the evidence that leads the majority of scientists to accept the more mainstream theory of 4.6B (+/- 0.2B) years, I might listen to the Young Earth types.

                  Similarly, I am sure you can find a scientist to claim Mars couldn't possibly have been wet. If and when they can explain away all the evidence that leads the majority of scientists to accept the more mainstream theory of "wet Mars", I might listen to the Dry Mars types.

                  And if you don't like that, blow it out yer arse.

      2. Turtle

        @Grikath: Re: Rocks.

        "which other liquid would that be then, pray tell?"

        You didn't understand my question. It was a "question". I didn't ask it because I know the answer. I asked it because I would like to know the answer.

        I did however understand your answer, which clearly told me that you don't actually know enough to answer my question - or, that you think that question is so naive as to be worth ridicule.

        Here's my question again: How do they know that the liquid that created the features of Mars under discussion was actually water and not some other liquid (such as found on other planets and moons)?

        Please, do one of the following two things: Either show me the evidence that proves beyond doubt that it was water and could only have been water, and shows that no other capable liquid could occur on Mars other than water (and since you deemed my question worthy of ridicule, I am expecting a very simple and obvious answer) - or, failing that, you can, alternatively, admit that you actually don't know enough to answer my question and that your smug superciliousness is due to your lack of understanding and knowledge.

        Thanks!

        1. Trevor_Pott Gold badge

          Re: @Grikath: Rocks.

          "show me the evidence that proves beyond doubt that it was water and could only have been water, and shows that no other capable liquid could occur on Mars other than water (and since you deemed my question worthy of ridicule, I am expecting a very simple and obvious answer)"

          Nothing can be proven beyond doubt. Exhibit A: moon landing deniers.

          That said, there are plenty of things on Mars which we've turned up so far that individually are highly likely to be the result of water and cumulatively almost guarantee it. Various clay and mineral deposits (which include things that have water locked up in their crystal matrices), the particular patterns of sedimentation and, IIRC, the rates and patterns of weathering are all evidence for water on Mars. And very specifically water, as opposed to another fluid.

          There are other items - for example some sedimentary deposits - that could have been the result of multiple fluids. (Yes, there are sedimentary deposits that fit in both categories.) Unfortunately for the "not water" hypothesis the cumulative evidence says that it is unlikely to the point of irrelevant that there were two different fluid cycles on the planet.

          Is it theoretically possible that some completely novel set of chemical interactions took place on Mars that just happens to look exactly like water? Sure. I also could have been switched at birth with the Trevor Pott from an alternate universe. It's just really, really unlikely.

          So unlikely that it's up there with "god actually exists". It's not worth considering unless and until we learn some really outrageously new science that could even begin to explain the evidence but reach a different conclusion.

          A scientist is always open to the possibility of the bizarre. That said, the business of science is one of probabilities, and science rests on the business end of Occam's razor. Right now, today, water is the only fluid that fits the evidence. What's more, it's the only fluid we know of that can fit the evidence.

          Thus, until someone can come up with a means by which another fluid can fluid the evidence, Mars has a wet past, a thick atmosphere and was warm. Given the evidence thus far, alternative hypothesis have a heck of an uphill climb to overturn current theory in this regard.

    2. Steve 114
      Pint

      Sandwiches

      Or even some other layering process followed by pressure consolidation. Beer for Mr Occam while he shaves.

  4. Will Godfrey Silver badge
    Thumb Up

    Fascinating Picture

    That just somehow seems to bring Mars closer

  5. Faux Science Slayer

    "Mommie, Can We Play Obombie Truth Origami"

    Any mass between a warm body and a heat sink delays thermal transfer. Earth is both warmer and cooler than the Moon, which is the same distance from the Sun and subject to the same heat input for three reasons. First is the Earth's atmosphere which filters out 30% of the incoming solar energy, COOLING the planet by day and delays outgoing heat loss by night, WARMING the planet. Second are the oceans which absorb heat, then transfer by Latent Heat of Vaporization surface energy into high altitudes where the energy is released by Latent Heat of Condensation, COOLING the planet. Finally Earth has a variable, internal fission that keeps the core molten at up to 10,000F while the Moon's core is only 40 Kelvin. These processes are described in the titled "Obombie Truth Origami" and "Greenhouse Gas Ptolemaic Model", both at FauxScienceSlayer site.

    Mars likely had active internal fission, a resulting protective magnetosphere, surface water and an atmosphere, which all appear to have ended about the same time as the massive Moon sized impact crater happened. This blow could well have dislodged the constantly diminishing air and water. Triassic flying insects and reptiles had twice the current flying animal wing span because there was at least twice, and because lift is a function of area, more likely four times the current sea level air density. Earth has lost that much atmosphere in 60 million years.

    1. Steve the Cynic

      Re: "Mommie, Can We Play Obombie Truth Origami"

      You know, I've been reading ... stuff ... on the Internet long enough that I can't tell anymore whether this is just someone trolling us, or if the writer is truly sincere.

      1. Wzrd1 Silver badge

        Re: "Mommie, Can We Play Obombie Truth Origami"

        Both true believers and also foreign players in information warfare.

        I've had teams actually track them through darknet.

        No, details will not be forthcoming, just as details were not and still not forthcoming on how TOR was cracked when I mentioned it, long ago.

        I *do* have an NDA.

        So, to be honest, after studying tactics, techniques and practices, I'm really not sure where this village idiot is coming from. Could well be a true village idiot, could as well be a paid troll.

        At the end of the day, I really don't give a shit.

        My rule has always been, "Ignore assholes". But, I do consider potential impact and speak now, barely, hobbled by a few NDA's.

        Two of which have criminal harm visited upon the breacher.

        First lesson in this world we're suffering through. There is cyber warfare. There are multiple components, defense, intelligence gathering and operational operations. On the net, operational means either penetration of networks of information warfare. In the latter, we see a *possible* candidate.

        But, to be blunt, the idiot isn't really worth my time to look at possible past entries.

        My previous physics and chemistry based arguments are above the idiot's nonsense.

      2. James 51

        Re: "Mommie, Can We Play Obombie Truth Origami"

        I always thought the bigger insects were due to higher levels of oxygen.

        1. Anonymous Coward
          Anonymous Coward

          Re: "Mommie, Can We Play Obombie Truth Origami"

          "I always thought the bigger insects were due to higher levels of oxygen"

          And then came the Japanese who made them smaller yet more reliable and in greater numbers

        2. cray74

          Re: "Mommie, Can We Play Obombie Truth Origami"

          "I always thought the bigger insects were due to higher levels of oxygen"

          Yep. However, there's a recent bit of faux science circulating on the internet that says Earth's atmosphere got radically thicker for a brief period during the age of dinosaurs. As with most pseudo-science theories, it ignores (or is just ignorant of) contradictory evidence like temperature proxies and fossilized rain drop patterns indicating minimally-changed pressure over the last couple of billion years. The theory cherrypicks a few facts (e.g., "ancient flying insects were bigger"), dismisses any contradictory evidence with reasons boiling down to, "it contradicts me, so I'll reject it," and presents its simple and neat explanation to its followers.

  6. Dr Kerfuffle

    The chances of anything coming from Mars are a million to one - IMHO

    :-)

    Paul

    PS. But still they come!

    1. Vic

      The chances of anything coming from Mars are a million to one - IMHO

      Yes, but million-to-one chances, as we all know, crop up nine times out of ten

  7. Gary Bickford

    Best headline ever!

    You folks have outdone yourselves with this one! :D

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