|Above: Streaks on martian slopes, believed to be due to brine water.|
But that might not be the best way to find evidence of life: Mars took aeons to die, and any life there would have evolved to protect itself - and it might have followed the same adaptation processes organisms on Earth have for extreme dryness.
That'd mean the right tactic to find it would be following salt, not water, according to Dirk Schulze-Makuch, an astrobiologist at Washington State University.
"There is a predictable sequence of how organisms adapt to increasing dryness," he told Space.com.
Eventually microbes seem to hit on the trick of living inside layers of salt crystals - particular types of salt will suck moisture out of even Mars-dry air and form brine water. Liquid brines within salt crusts might have served as the last available habitats for life near the Martian surface, Schulze-Makuch said In fact, in this way Martian life might have survived to ths day
Ordnance Survey releases Mars map
OS is brand of map very well known to anyone who has gone hiking in the UK - at least, if you've been serious about not need the mountain rescue guys. Their maps have been a staple of woodland and mountain explorer's backpacks for decades. Now they're going where few mappers have gone before, and released a map of the planet Mars! Are they telling us that some of the backpaths in the Peak District lead to much further afield than we thought? That would explain the odd missing backpacker....
Fungi survive Mars conditions for 18 months
The McMurdo Dry Valleys, located in the Antarctic Victoria Land, are considered to be the most similar earthly equivalent to Mars. They make up one of the driest and most hostile environments on our planet - most of the time it's too harsh even for snow to fall. Only microorganisms, capable of surviving in cracks in rocks, grow there - and only very slowly. But these hardy critters may have the stuff to survive in a harsher environemnt still: Mars. On the international space station, samples antarctic microbes were exposed to Martian conditions for 18 months... and nearly two thirds of them have survived.
Elsewhere in the Universe:
Possible second gravitational wave source detected