Phoenix Team Divided: Are the Mars Liquid Water Observations a “Matter of Belief”?

Article written: 10 Mar , 2009
Updated: 24 Dec , 2015
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Last month, it was announced that in the few days after the landing of the Phoenix lander in May 2008, the camera attached to the robotic arm captured visual evidence of (what appeared to be) droplets of water, almost like condensation forming on the leg of the lander. In three images dated on sol 8, sol 31 and sol 44 of the mission, the droplets appear to move, in a fluid-like manner. Although a recent publication indicates this oddity could be a water-perchlorate mix (where the toxic salt acts as a potent anti-freeze, preventing the water from freezing and subliming), other members of the Phoenix team are very dubious, saying that there is another, more likely explanation…

One of the key components necessary for the survival of life on Earth is water, especially when the water is in a liquid state. This is an easy proposition on our planet, as the atmospheric pressures and temperatures are just right for the majority of water on Earth to be in a usable liquid state. Should liquid water be discovered on another planet however, where the conditions are often too hot or too cold (or when atmospheric pressure is too low) for water to be found in a liquid state, you’d expect there to be some excitement. When that other planet is Mars, the focal point of the search for basic extraterrestrial life, this excitement will be tempered with intense scrutiny.

In February’s article, Nilton Renno from the University of Michigan and Phoenix mission team scientist, announced results from his team’s research into some odd-looking blobs on one of the lander’s legs. Renno’s hypothesis, to be presented on March 23rd at the Lunar and Planetary Science Conference in Houston (TX), focuses on the possibility that the newly discovered toxic compound, perchlorate, may hold the key to the possibility of liquid water on the Martian surface. We know on Earth, briny (salty) water has a lower freezing point than pure water, and Renno suspects that this might be the case for water on the surface of Mars. However, rather than regular salt, the toxic perchlorate salt is mixed with water in the regolith, allowing it to sustain its liquid state.

Although a very interesting proposition, Renno’s results are based on only photographic evidence of what appears to be blobs of water. Other Phoenix scientists are emphasising that the theory is controversial, citing far simpler answers for the observations.

There’s a matter of belief at some level,” said Peter Smith from the University of Arizona in Tucson and principal Phoenix investigator. “I can’t say I agree with every statement in the [Renno] paper.”

Michael Hecht, the lead scientist for the instrument that discovered perchlorate in the first place, goes as far to say a perchlorate brine on the Martian surface is very unlikely. Simpler explanations for the apparent dynamic movement of the “liquid” blobs could be attributed to changing shadows. Although perchlorate acts as an efficient “sponge”, condensing water vapour from the surrounding air, the temperatures stated in the paper are actually too warm to form liquid droplets of perchlorate brine.

I just don’t think it’s the likely explanation,” Hecht said. “It’s just plain old frost, nothing more.”

Looking at the Phoenix images (top), I am a little suspicious about the lifetime of these proposed “liquid” droplets. From sol 8 to sol 44, there is little dramatic change in the locations or sizes of these features. 36 sols of long-term droplets of liquid water seems like a very long time considering the very low atmospheric pressures we are dealing with. Surely liquid brine droplets will dissipate (through evaporation, rather than sublimation) far quicker than 36 sols? Granted, there may be further condensation from the atmosphere (topping up the presence of the liquid), but wouldn’t there be more motion in the blobs if this were the case? This said, I am not familiar with perchlorate brine, so this might well be a characteristic of this cold liquid.

It looks like Renno’s research will make for a very interesting presentation on March 23rd at the Lunar and Planetary Science Conference, sure to provoke a lively debate…

Source: Space.com

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Hello! My name is Ian O’Neill and I’ve been writing for the Universe Today since December 2007. I am a solar physics doctor, but my space interests are wide-ranging. Since becoming a science writer I have been drawn to the more extreme astrophysics concepts (like black hole dynamics), high energy physics (getting excited about the LHC!) and general space colonization efforts. I am also heavily involved with the Mars Homestead project (run by the Mars Foundation), an international organization to advance our settlement concepts on Mars. I also run my own space physics blog: Astroengine.com, be sure to check it out!


19 Responses

  1. the_nthian says

    We’re talking about , what amounts to , welding under extremely low pressures when you consider there were a bunch of rocket engines blazing away as it touched down.
    What effects might be imagined if this were a factor to be considered?

  2. Damian says

    OR:

    The Liquid water (where and when it exists) on Mars is suffused with a (Martian life form) Helping it to maintain its shape, grow and multiply.

    As the observations are speculations anyway, why not speculate wildly and with gusto. 🙂

    Damian

  3. Concresence says

    This is how it starts. A few scientists innocently remarking, “Hey, I wonder what those drops of strange liquid are? Wish we could get a sample . . .”

    Three years later we are all hosts to a race of parasitic, blood-thirsty, power-hungry microbial aliens.

    Wonderful, just wonderful.

  4. Mr. Greenjeans says

    Based on the content of the various news feeds, it sounds like this has been thoroughly explored. It also sounds like no matter how they explore it, the results will be the same: inconclusive. I think it’s time to move on.

  5. Kevin F. says

    Just proof we really need to put a video camera on one of these landers. Yes, it will be a long upload from Mars and a live video feed near impossible – but if we would have had video of the “droplets” sliding.

    Plus video of a martian dust devil would be cool, no matter how crappy the resolution.

  6. MJG says

    “Three years later we are all hosts to a race of parasitic, blood-thirsty, power-hungry microbial aliens.”

    Hmmm…methinks that this might be better than our current infestation of parasitic, blood-thirsty, power-hungry politicians.

  7. Hi Universe Today – huge favor to ask? Every time you point out how toxic perchlorates are, can you also include that they are extremely inert when in solution with water? There are microbes on Earth that survive in and metabolize perchlorates just fine. All the talk of toxicity has been making for some awful fodder in the papers (“Mars Uninhabitable”) when writers are looking for something with grab.

    Thanks!
    ~]3

  8. TD says

    My heart goes out to the Phoenix scienctists and engineers who worked hard on this mission. But to have made a daring landing on Mars, to have the incredible luck of the rockets engines moving enough top soil and then melting enough ice to splash drops on the lander leg, and not even know if that’s water…..is that pathetic or what? I thought the strategy to find life was to “Follow the Water”…we’ve been hearing that for years…….well, I guess we found it. Now what? Think it’s time some real life-detection probes?

  9. TD says

    And it would be nice, if we ever plan to look for life on Mars, to ask the Planetary Society to delay sending a titanium “hockey puck” full of microbes in that direction. If that experiment breaks open and scatters earth microbes, or even just goes missing, how will we ever know that a future discovery of life on Mars, with any genetic relationship to Earth life at all, wasn’t the result of contamination?

  10. Nephish777 says

    Interesting comments. The way the numer of the patches increased, I believe that it is frost. There is enough water for snow and the tempature is certainly cold enough for water to form frost. Since CO2 freezes at about -100 degrees fahrenheit (-73 C), I doubt the patches are “dry ice”. (However by now Phoenix is most likely buried in snow and “dry ice”. Hope it wakes up in its spring.

  11. Bill Davis says

    I suspect electrodeposition, perhaps of charged dust agglomerates. This is supported by the incredible cohesion of the dirt samples – recall the difficulty in getting the samples through the screens – which I think was due to none other than “static cling” i.e. charge buildup. When the charge dissipated into the metal of the lander, the sample material fell through the screens into the bins.

  12. Feenixx says

    Kevin F:
    Phoenix DID take a series of shots of a dust devil, and NASA assembled them into a very cool movie movie.

    Mr Hecht, I sincerely hope that somebody has quoted you incorrectly:
    Any scientists explaining what everybody can see as drastic changes in size (and also considerable changes in position) of those unexplained objects as “shadows” pretty much invalidate their qualification to make useful observations, imo.
    And is there a mechanism which can produce SMOOTH BLOBS of frost? Even taking into account the very alien Martian atmosphere?

    BTW, does anybody know what the legs of Phoenix are made of? Would this, perhaps, help to solve the puzzle?

    For the time being, I suggest those blobs might be bird droppings… 😉

  13. ThereIsNoSuchThingAsMagic says

    It makes me wonder how difficult it would be to re-create the conditions in a lab, as closely as possible ( Mars gravity will be a problem ), and just see what happens? We know the atmospheric conditions, temperature and makeup, we know phoenix’s makeup, and also the composition of the regolith and ice underneath…How possible would it be to perform such an experiment?

  14. JoeTheRationalist says

    I’m sorry but I don’t see anything moving.

    What I see is dust coating and uncoating pebbles and building up small dunes around the pebbles making them appear in different shades and sizes.

    There. Mystery solved.

    Stop extrapolating please – stick to the evidence.

  15. ThereIsNoSuchThingAsMagic is correct to ask why not replicate the lander environment? In fact, it is perfectly clear that no one had any real idea of the operating environment Phoenix was to be dropped into. The design of the ovens that were far too small to readily accept a frozen dust/water sample is just one example. Now I agree that my accusation might be seen as unfair, considering that overall they did bring in a result. But that is not the point here.

    The point is, it is perfectly clear, no one has any experience of the Mars surface environment. Look back at the early problems with spacecraft. NASA had a team able to work out problems in real time. Phoenix should have such a team. But to create such, you need a specific facility dedicated to replicating the actual surface conditions.

    Having designed, manufactured and commissioned the first Freeze Drying Microscope for PHLS-CAMR through another company I own, (but which has been dormant for some years now, UK Research & Development Limited), which allowed real time observation of samples down to -100C I can say that I have real first hand experience of designing the same environment. I will be pleased to help.

    I remain astounded that NASA do not appear to have such a facility, have no way of replicating the conditions, and show no sign of recognising a need for one.

  16. Water has been “discovered” on the surface of Mars several times now.
    It is a well known fact that if a salt is disolved in water it will lower the temperature at which it freezes.
    When the Mars team talk about water when they really mean a salt solution this should be clarified and where possible candidate salts suggested.

  17. Feenixx says

    JoeTheRationalist Says:
    I’m sorry but I don’t see anything moving.

    Neither does anybody else. These are still images. 😉

    However: the first two images show blobs of different sizes in different locations. This suggests that
    either
    a) they have moved and/or changed over a period of 23 days
    or
    b) they disappeared and new ones formed instead

    JoeTheRationalist also suggests:
    “Stop extrapolating please – stick to the evidence”
    immediately after he extrapolates:
    “What I see is dust coating and uncoating pebbles and building up small dunes around the pebbles making them appear in different shades and sizes.”
    What he means: He IMAGINES dust coating and uncoating pebbles, etc., etc…
    However, I can’t see pebbles clinging to the legs of Phoenix (which are sticking up at a steep angle) and becoming covered and uncovered by dust as a view a rationalist would come up with.
    Sorry about that. Feenixx The Agnostic, for his own sanity and peace of mind, sticks with: “Nobody has a clue, no matter what they say.”

  18. Damian says

    Its an alien concept, water suffused with life. 🙂
    I read somewhere that human beings are mostly water.

    Heres a possible scenario.

    Mars Once did have liquid water, An ocean in its northern hemisphere certainly. Supposing microbiological life did evolve, but as the planet suffered its slow decline, the life adapted the water. We think of water as a liquid, even as a frozen solid, but on mars the life adapted to create a quazi state, not quite solid and not quite liquid.

    Perhaps almost a Gel?

    We see it all over mars today, fringing the CO2 icecaps. In the bottom’s of craters and around the poles where its warmest. (The North Ice cap dune fields are the largest such structures in our solar system to date)

    In reading the accounts of so many experts, We hear how the (strong) winds on mars have shaped the Sand dunes, yet mars cannot have strong winds. The low atmospheric pressure on mars means that strong winds cannot exist. Yet mars is covered in amorphousness wave like structures that show seasonal change and seem to only exist in lower latitudes, possibly where the pressure allows their survival. (I haven’t found any in high latitudes yet)

    Its my (conjecture) that Mars’s Pac-Man sandunes and pebble like blobs on the legs of the lander are one and the same.

    And both the sole repositories of the self same liquid water from Mars’s distant past.

    Clumpy, no wonder they didn’t want to go in the ovens to be analyzed. 🙂

    Conjecturing with gusto and left of field imagination. I have no proof, but its an interesting consideration. Would not life (alien), in its bid to survive, by now have used every last drop of water available to it on Mars? Formed itself into structures to prevent the solar wind and radiation from stripping it all away?

    Damian

  19. redcloud says

    Talking about contamination risks, C. McKay had a nice piece about the subject on a recent Science.
    As for the clumps on the legs of the probe… why are there alterations on those two, while the others seem to be pretty much the same (apart from some apparent growth) from sol 8 to 44?

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