Liquid Water on Mars?

Water droplets appear to be growing on Phoenix's leg shortly after landing on Mars (NASA)

Water droplets appear to be growing on Phoenix’s leg shortly after landing on Mars (NASA)

NASA scientists are currently trying to understand a set of images taken by the Phoenix Mars Lander shortly after it landed on the Red Planet in May 2008. The images in question show one of the robot’s legs covered in what appears to be droplets of liquid water. The droplets remain on the lander for some time, appearing to get larger and changing shape.

By now, we know that liquid water (apparently) hasn’t existed on the Martian surface for hundreds of millions of years; the atmosphere is currently too thin and too cold to support liquid water. However, the confirmed presence of perchlorate in the regolith may provide an important clue as to what might be going on…

In August 2008, the Phoenix Mars Lander had discovered something… provocative. It was one of those extremely lucky space blogging days, when I stumbled across an Aviation Week article entitled “White House Briefed On Potential For Mars Life“. Technically, the article was correct, but the added secrecy about some discovery being passed to the President before being made public seemed more conspiracy theory than scientific theory. However, I blogged like I’d never blogged before and got this breaking news onto and the Universe Today in record-breaking typing speed (yes, 50 words per minute is record breaking for me).

I was immensely happy to be up there in the first few bloggers who had posted the news first, but the web traffic tidal wave that ensued knocked both sites offline. It was mayhem, especially for Astroengine. In the first day, I think I got washed away with 50,000 visits from various social bookmarking sites, I have no clue how many slammed the Universe Today server, but it was a lot.

However, the facts behind the headlines weren’t 100% clear. “Potential for life” didn’t necessarily mean it was going to be news of Martian cockroaches setting up home under Phoenix, it was actually the opposite. A toxic chemical called perchlorate had been discovered, more of a hindrance than an advantage to life as we know it. Bummer.

But like all good Mars research projects, there’s a flip-side to this potentially disastrous news; perchlorate is a salt. What does salt do when dissolved in water? It lowers the freezing point of water. Therefore, if perchlorate exists in the Martian regolith, it may also be dissolved in the water we now know (thanks, also, to Phoenix) exists there. Although the temperature never rose above -20°C at any point during Phoenix’s lifetime, perchlorate turns out to be a very potent antifreeze substance, allowing water to remain in a liquid state regardless of the extreme atmospheric temperatures down to -70°C.

Although far from being conclusive evidence about the existence of liquid water on the Martian surface, these Phoenix images do appear to show droplets of water on the lander’s leg. Before the discovery of perchlorate salt in the regolith, these images would probably have been written off as a curiosity, but now NASA scientists are actually entertaining the thought that liquid water can exist on the surface.

But how did the water get on the leg? Either, the Phoenix rocket landing boosters melted a layer of ice on the surface (possibly pure water-ice, melted and mixed with perchlorate, or a water-perchlorate ice mix), or a pool of existing liquid water (plus perchlorate mix) was already there. The lander dropped right in the middle of the puddle, splashing the leg with liquid water that would not freeze, captured in these images.

If liquid water exists on the surface of Mars, with the help of perchlorate, there could be a profound Martian irony: Although we understand perchlorate to be toxic to life on Earth, it might be provide life-giving liquid water to very basic forms of microbial life that thrive in briny fluids.

Perchlorate might be of some use after all…

For more, check out my article on the Universe Today: Has Liquid Water Been Detected On Mars?


6 responses to “Liquid Water on Mars?

  1. It’s a dang shame the evidence is so inconclusive… we’ll probably be arguing about this for years before we get confirmation one way or the other. Heck, people still argue about the results of the Viking experiments!

  2. Just to mention that Argentinian neuroscientists keep an academic tradition long involved with life definition & life concept. This allowed a reading, of exobiology-concerned planetary data, different from the one usual abroad. One of those scientists, a relative of Lt. General Gaetano Arturo Crocco who in 1956 first correctly designed a flyby to Mars, in 2006 was attracted to reconsider Levin’s claims that Viking Mission’s Labeled Release experiment found life. If not in the usual concept abroad, it’s true in the local concept.

    The scientist also proposed that exobiological holotypes are to be radioed patterns (because of security reasons preventing to bring and handle extraterrestrial holotypes on Earth), thus repeating in biology the progressive increase in the observer’s handling distance that also characterizes modern physics as an epistemological feature.

    Still the same scientist utilized those concepts and formally nomenclated the Viking’s LR radioed patterns as a description of metabolism (raher than of, say, legs, leaves, or wings) in a Martian organism. The name has been academically published as Gillevinia straata, a biologial organism by now featured upon its metabolism, and not belonging with Bacteria (which is a terrestrial kingdom) but to Jakobia, which is the kingdom created to accommodate it in the new biosphera Marciana.

    Back to the main track of this good synoptic article by Ian O’Neill: the mentioned scientist calculated the minimum amount of liquid water in powder+water ice at any temperature, discovering that, per every cubic centimeter of dirty ice, Van der Waals forces AS A MINIMUM constantly keep 90 cubic microns of liquid water at the interface around powder granules. This is enough to act as a solvent for the reactions lodged by such a values of metabolism as determined by the Viking LR data; the liquid outside an organism is replaceable (van der Waals forces don’t exhaust) and inside a biological organism may both adsorb excess liquid as well as keep available on exothermic reactions to deliver the necessary liquid amount. Later another independent researcher, Mohlmann, calculated not a minimum but a probable amount of liquid water ten to a hundred times larger.

    The work was published in Argentinian journals, which Google easily picks up. Some people who ignore the social problems affecting Argentinian science used that fact to skip over this work, which remains somehow undercommunicated. Thus I thought that making here this modest commentary might be of interest. I’m the director of one of the mentioned journals, now for a short time at the University of Valladolid (Spain).

  3. Pingback: Big AGU Announcements: Curiosity Team May Not, But What About Voyager 1? (Update) |

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