I read the following BBC article a month or so ago and was amazed by its contents.
NASA scientists think they have evidence that water is following on Mars. But there is a twist as the surface temperature is too cold to allow water to be liquid – so what on earth (no pun intended) is happening ….
…. well firstly, the liquid (notice I am not saying water) is only flowing during the Martian summer, when sunlight would be shining on the surface where the flowing liquid has been seen.
Secondly, scientists believe that the liquid would be brine (salt or sodium chloride dissolved in water). This makes the water ‘impure’ and hence lowers its melting point.
However, the implications with regards to life are huge and I am sure we will be hearing more about this phenomenon in the future. Maybe the Mars Rovers could be sent to investigate? 😉