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Wednesday, 15 April 2015

How to make water on Mars....

The idea that there might be water on Mars has been beguiling and fascinating us for decades. Why? Because, on Earth at least, water means life - and the idea of finding life on another planet fascinates us. It's been known for a while that Mars had plentiful water, even an ocean, billions of years ago.......

Above: NASA explains about the Martian ocean. They do a few cool things like this, have alook around youtube for them!

......and even in later epochs volcanoes would occasionally melt surface ice. But this week some new analysis of the Martian desert (here's the abstract in nature), drawing on both data from the Mars rover Curiosity and the fleet of orbiting space probes, has made it seem that much more likely there is some liquid water still on Mars today (link here).

What has been discovered is a natural antifreeze, called calcium perchlorate, in the soil at Curiosity's location. As well as being an antifreeze calcium perchlorate absorbs moistuire out of the surrounding environment, and when it has absorbed enough a perchlorate particle turns into a droplet of perchlorate saturated water. Here's a video of the process, which is called deliquescence, turning a tiny crystal of regular salt into a droplet under a microscope:

Above: No, that isn't an ice blockmelting, it's a tiny crystal of table salt absorbing enough water to become a droplet of hypersaline water.

On Earth hypersaline (very,very salty) water forms pools that stay liquid even down to -50 degrees celcius. On Mars the ability to stay liquid at low temperatures has a double benefit: It keeps the water from freezing solid, and it keeps the liquid from evaporating away in the very thin atmosphere.

The Copenhagen team haven't found any lakes, but what they have done is use curiosity to measure how much water vapour the soil is absorbing out of the thin martian air - and it seems that enough is being taken up to form these antifreeze laden drops. The soil also contains evidence of these droplets migrating through the soil and into the ground. While this isn't as promising as a direct detection of water would be, it is an interesting find, and increases the chances that areas on Mars nearer the poles, with more vapour in the atmosphere, might be able to form enough water to support hardy microbes.

Above: Don Juan pond in
Antarctica, where the salts in the water keep it liquid even at minus fifty degrees celcius. Put your fingers in and... well that'd be waste of fingers. Courtesy of the British Antarctic Survey. 

Elsewhere in the universe:

Evidence for a Martian ocean, water activity in gullies,  and subsurface lakes:
The European Geophysical Union has given a press conference , outlining three new water related lines of evidence about Mars: The first speaker gives more evidence supporting the idea that Mars had an ocean in ancient times, the second talks about how some martian gullies may have formed by wet debris flows, and the third describes how large floods came bursting from underground resevoirs. The EGU haven't made a copy of this on embeddable yet, so here's the link.

Even more on Marian water: Martian mountain might be 'leaking':
A mountain system on Mars shows signs that rust and salt polluted water might be leaking out from underground reservoirs on a yearly basis.

Above: The redder streaks running down this mountain might be formed by rust polluted water running down the flanks until it evaporates. Or not. If it is, and you're reading this from Mars near that mountain (anything is possible), don't drink the stuff. Courtesy of HiRiSE

SpaceX successfully launches supplies and experiments to the space station, but just misses re-usability goal:
Elon Musks SpaceX company has successfully launched one of their Dragon spacecraft to the international space station, with a cargo of supplies and experiments. The company came close to landing the rockets first stage on its ocean barge/landing pad,  but it toppled over and broke into pieces moments after touchdown.

Above: Ooooh.... that was so close! The rocket actually lands safely on the pad,but just after this finishes it fell over! I'll take the glass half full point of view - this bodes really well for the next try! Courtesy of SpaceX.

Vulcan rockets to launch in 2019, will try a different take on re-usability
The ULA designed Vulcan rockets will parachute their engines back to Earth. Facing ever stiffer competition,  and demand for lower prices, United Launch Alliance is hoping its innovative design wil help it keep its competative edge.

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