Universe Today: short-term liquid water on Mars?

By Phil Plait | February 19, 2009 2:00 pm

Ian O’Neill at Universe Today has an interesting story on some possible (temporary) liquid water spotted on the leg of the Phoenix lander shortly after it touched down on Mars. The images are interesting, but not convincing. Still, it’s an intriguing story and it’s worth investigating. I don’t have any more information than Ian does, so head over to UT and leave your comments there.

CATEGORIZED UNDER: Astronomy, Cool stuff, Science, Space

Comments (18)

  1. Pool party on Mars! Woo!! *splash*

    …brrrr…..

  2. Brian

    Liquid water on the leg of the Phoenix lander? Have they ruled out the possibility that it was from the Mars Rover?

    Bad Rover! Bad Rover!

  3. It turned out that the Phoenix instrumentation had found quantities of a toxic chemical called perchlorate known to be a hindrance to life as we know it.

    Emphasis mine. I know that over on the JREF forums, we really seem to be quite hindered by our singular datapoint. It’s because of this that we NEED a manned mission to Mars that can get down in the nitty gritty to really LOOK with sensetive instrumentation. I don’t think we have (or will have in the near future) any robot technology that dan do work like a human being. We keep saying “life as we know it” but that just applicable for earth. We’re dealing with so many unknown factors that we really can’t say what it is that we really DO know.

    Steps of his soapbox and joins Bunny in the pool.

  4. Savino

    Damn, I was expecting oil! :(

  5. LOL, Savino, if it had been oil, we’d have multiple manned missions on the way! :D

  6. Steve A

    The UT story was originally published at New Scientist. They have another article that relates about how perchlorate can act as antifreeze to keep water in a liquid form at very low temps.

  7. Naomi

    Ooh, that IS interesting! I’d love to see how those investigations pan out – the idea of microbial Martian life in pools of perchlorate-rich water is pretty cool ^_^ (Pun, er, mostly unintended XD)

    I watched episode five of Cosmos today, so I’m in a “Yay Mars!” mood right now ^_^

  8. Bein'Silly

    @ Brian Saying : “Liquid water on the leg of the Phoenix lander? Have they ruled out the possibility that it was from the Mars Rover? Bad Rover! Bad Rover!

    LOL! Good ‘un! :-D

  9. Doug Ellison

    If it actually saw LIQUID water on the landing legs – wouldn’t it have been observed trickling down the landing leg onto the surface?

    What they saw was funny nodules of ice on the landing legs, probably caused by the >1000degC landing rocket exhaust plumes excavating the soil to the ice layer, seen as Snow White and Holy Cow under the lander a few sols later.

  10. Gary Ansorge

    Naw, it’s just a local life form trying to take a bite out of the landers leg,,,

    GAry 7

  11. Torbjörn Larsson, OM

    Ah, cool! (Or wet? :-) I seem to remember Emily Lakdawalla over on Planetary Society blog speculating about those blob after their discovery, only to overlook the report on their putative liquid status when she linked to the 40th Lunar and Planetary Science Conference program. I was miffed at the time. ;-)

    wouldn’t it have been observed trickling down the landing leg onto the surface?

    You can look up the report above, but IIRC they not only observed them move downslope, but some coalescing. That seems hard to explain without assuming that the blobs are semi-liquid at least part of a sol.

    It turned out that the Phoenix instrumentation had found quantities of a toxic chemical called perchlorate known to be a hindrance to life as we know it.

    I’m not a chemist, but I don’t get why Ian O’Neill persists in claiming “hindrance to life”, on UT and IIRC on his blog. Googling perchlorates IIRC only gets me reports of toxicity for animals with nervous systems – among other things it seems to really mess with fish brains already at low concentrations.

    I have no doubt that organisms that have evolved in an environment containing such a weak oxidizer would be able to benefit from it, especially in a Mars environment where it AFAIU is mostly inert in situ.

    After all, earthly organisms have evolved intricate systems to not only handle but actually benefit highly from what I believe to be a much more toxic and potent oxidizer at extremely high concentrations. It is called oxygen…

    And at the same time it is ironic that O’Neill glides over the difficulties that organisms have to evolve wholesale in extreme environments such as “very salty fluids”. Most abiogenesis theories seems to have life starting out in relatively benign conditions since it is hard to envision for example membrane self-assembly otherwise, and it is by later evolving what I understand to be fairly intricate mechanisms for growth, protection, and self-repair that organisms can survive the more extreme milieus of an oxygen atmosphere or, seemingly even more difficult, high salinity. Talk about “hindrance to life”.

  12. Charles Boyer

    I have been meaning to do the math forever, but wouldn’t the current temperature and vapor pressures on Mars favor sublimation of ice to water vapor more so than liquid water?

  13. Thank you Phil! It was one of those, “I should really be getting to bed– oh hell, liquid water on Mars? Back to the computer!” moments when I saw the news pop up on the ‘net. So happy I’m a night owl.

    However, I was a little surprised there wasn’t more of a buzz about this. Is the world getting a little Mars-desensitized? I hope not. Mars rocks.

    Cheers! Ian

  14. The original LPSC paper is here:

    http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1440.pdf

    See also the NewScientist article:

    http://www.newscientist.com/article/dn16620-first-liquid-water-may-have-been-spotted-on-mars.html

    They help explain why the 21 scientists involved (including Peter Smith, the mission’s lead scientist) think these were liquid droplets, not just frost or soil clumps, etc., notably that the “droplets” were observed to grow and two of them merged together in a manner similar to that expected of liquid (ie. briny water). The droplets could have either come from an already existing thin liquid brine layer or created by the thrusters that melted a thin layer of the ice patch below the lander and the perchlorates that got mixed in could have kept them liquid. The largest ones even _look_ like liquid droplets (more so than frost or soil clumps anyway). There’s also a theory that hydrazine from the thrusters may have been mixed into the droplets, which could also keep them liquid for longer than normal.

  15. Doug Ellison

    Compared to the surface it was standing on – Phoenix was a massive thermal anomaly with much of it’s >2kwhr/sol energy budget spent on heating itself. That water might, for a time, melt on its legs is not that unusual. Every headline I’ve seen is at least partially misleading – there wasn’t liquid water observed ON MARS, it was observed ON PHOENIX. I’m not suprised it’s not big news. “Ice hits warm metal leg….melts for a while’ – not groundbreaking. If one of Phoenix’s trenches had filled up with water – THAT would have been extraordinary – but as we saw – ice simply sublimated out of them.

  16. For those who haven’t seen it, the original LPSC paper is here:

    http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1440.pdf

    Tthe NewScientist article:

    http://www.newscientist.com/article/dn16620-first-liquid-water-may-have-been-spotted-on-mars.html

    This and the NewScientist article help explain why the 21 scientists involved (including Peter Smith, the mission’s lead scientist) think these were liquid droplets, not just frost or soil clumps, etc., notably that the “droplets” were observed to grow and two of them merged together in a manner similar to that expected of liquid (ie. briny water). The droplets could have either come from an already existing thin liquid brine layer or created by the thrusters that melted a thin layer of the ice patch below the lander and the perchlorates that got mixed in could have kept them liquid. The largest ones even _look_ like liquid droplets (more so than frost or soil clumps anyway). There’s also a theory that hydrazine from the thrusters may have been mixed into the droplets, which could also keep them liquid for longer than normal.

    Doug – first you said it must have been ice, now you seem to accept the idea of liquid water droplets?

  17. Sorry for the duplicate comments – for some reason my original comment from a few days ago now, never showed up, so I tried again, and now both have shown up at the same time – ?! Can the first copy of my comment be removed? I tried posting the same comment in the Universe Today story and it still hasn’t shown up yet either!

    The three comparison images shown in the NewScientist article were taken on the 8th, 31st and 44th sols, a long time for just a bit of “ordinary ice” to melt on the leg and remain liquid in the Martian conditions, which is why brines are seriously being considered by the Phoenix team. Again, the original LPSC paper and NewScientist article already explained this, for those who read it before jumping to premature conclusions.

  18. There is another new update on The Planetary Society Blog, including comments on why the Phoenix team et al, think the droplets were salty water brines and not just ice or frost and unlikely to be the result of hydrazine, etc. from the engine thrusters mixing in with melted ice:

    http://www.planetary.org/blog/article/00001890

    Excerpt:

    “The first question that comes to mind is “Why don’t they think the spheroids are made of ice, not liquid water?” They argue that ice particles wouldn’t have formed in spheroids, they would have formed a thin, uniform layer, much like the frost coating seen later in the mission. For the spheroids to be ice at the observed weather conditions, the humidity would have to be higher than 100%. Also, toward the end of the mission, when frost was abundant at the landing site, ice spheroids should have grown in volume rather than shrinking. Ice couldn’t form on the lander leg unless the leg was colder than the ice, but engineering data returned from the lander shows warmer temperatures.

    The next question that’s most often asked is “Couldn’t the thrusters’ composition have contaminated the landing site?” The answer is that Phoenix definitely disturbed her landing site; however, there is no evidence Phoenix chemically altered the site. If any ice was melted by the thrusters, it would have quickly turned into a vapor and not have turned into a liquid. After landing, several containers were vented, and all were on the opposite side from the spacecraft from where the robotic arm’s workspace, and thus also the leg that showed these spheroids. The engineering data doesn’t show that there was any hydrazine left to vent, and had there been, it would have been a solid at Phoenix’s site due to the low temperature. Any byproduct of the hydrazine would not have caused the spheroids either.”

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