Briny Water May Pool In Mars' Equatorial Soil

astroengine writes Mars may be a frigid desert, but perchlorate salts in the planet's soil are lowering the freezing temperature of water, setting up conditions for liquid brines to form at equatorial regions, new research from NASA's Curiosity rover shows. The discovery of subsurface water, even a trickle, around the planets warmer equatorial belt defies current climate models, though spacecraft orbiting Mars have found geologic evidence for transient liquid water, a phenomenon termed "recurring slope lineae." The findings, published in this week's Nature Geoscience, are based on nearly two years worth of atmospheric humidity and temperature measurements collected by the roving science laboratory Curiosity, which is exploring an ancient impact basin called Gale Crater near the planet's equator. The brines, computer models show, form nightly in the upper 2 inches of the planet's soil as perchlorates absorb atmospheric water vapor. As temperatures rise in the morning, the liquid evaporates. The levels of liquid, however, are too low to support terrestrial-type organisms, the researchers conclude. "It is not just a problem of water, but also temperature. The water activity and temperatures are so low in Mars that they are beyond the limits of cell reproduction and metabolism," Javier Martin-Torres, with Lulea University of Technology, in Kiruna, Sweden, wrote in an email to Discovery News.

Comments

Martian water is hypersaline

[Geoffrey.landis]

Yes, I've mentioned this before-- if there are bacteria on Mars, they will be extreme halophiles.
http://online.liebertpub.com/d...
http://ntrs.nasa.gov/search.js...

Yeay!

[Rei]

What great news for the prospect of life on Mars! Quantities of a chemical that destroys organics on contact are so great that they suck water out of the soil and air!

Nasa's massive obsession with this self-sterilizing rock come at the cost of investigating much more interesting targets elsewhere in the solar system. The money going to Mars 2020 in particular could do so much elsewhere (we really could use a followup to Titan, there's so many mysteries there we're not even close to solving, while new missions to Mars are more trying to find new mysteries to solve and answering the same vague "questions" over and over again) At least Europe is going to get something now - not my personal favorite (if there is anything interesting there, which we don't actually know, it's buried way too deep for us to get at it for a long, long time). But at least it's not NASA's "All Mars Channel".

Re:Yeay!

[Sowelu]

Mars takes ~260 days to reach, with a payload that could theoretically bring humans...maybe 130 if we do some pretty crazy stuff. Europa takes three years minimum for a much smaller payload. Actually getting humans to Mars is already a big technical challenge, let alone living once we get there...it's going to take a heck of a lot more practical experience before we can get them to Europa.

Say what you want about the pointlessness of living off-world, but Mars is great practice. It's closer, it has more solar power available, and we can send bigger things with our current technology. Same with the Moon...great practice, but even less practical reasons to be there than Mars.

Re:Yeay!

[Rei]

If your goal is living offworld, the most earthlike place in the solar system outside of Earth is the cloudtops of venus. A person could walk outside in shirtsleeves with just an oxygen-providing and eye-shielding face mask. Ordinary earth air is a lifting gas. Gravity is 0,9g. Aerocapture is simple. Water can be condensed straight from the cloudtops and oxygen hydrolized with the abundant solar power. There is zero dust to gum up the works (and the SO2 aspect is overplayed, even in the clouds it's not that concentrated).

If your goal is science, Mars isn't the place either, it's been way more studied than everywhere else but Earth and possibly the moon. People differ about what's the most scientifically interesting place but I'd argue that Titan has the most interesting unanswered questions.

If your goal is a colony that stands a chance of paying for itself (good luck with that), your best bet is an asteroid or cometary body (potentially with ice / CHONP, otherwise they can be shipped in with little delta-V from other asteroids / comets) that has abundant valuable metals in concentrated, non-oxidized forms for mining with little delta-V reqs for earth return or space use.

If your goal is a self-sustaining colony (a "backup earth" or whatnot), step out of the sci-fi novels. We're centuries away from that at best.