Nasa’s Curiosity rover finds water below surface of Mars | Science | The Guardian
▻http://www.theguardian.com/science/2015/apr/13/nasas-curiosity-rover-finds-water-below-surface-of-mars
Mars has liquid water just below its surface, according to new measurements by Nasa’s Curiosity rover.
Until now, scientists had thought that conditions on the red planet were too cold and arid for liquid water to exist, although there were known to be deposits of ice.
Prof Andrew Coates, head of planetary science at the Mullard Space, said: “The evidence so far is that any water would be in the form of permafrost. It’s the first time we’ve had evidence of liquid water there now.”
The latest findings suggest that Martian soil is damp with liquid brine, due to the presence of a salt that significantly lowers the freezing point of water. When mixed with calcium perchlorate liquid water can exist down to around -70C, and the salt also soaks up water vapour from the atmosphere.
New measurements from the Gale crater show that during winter nights until just after sunrise, temperatures and humidity levels are just right for liquid brine to form.