At http://phys.org/print362657730.html … NASAs Mars Reconnaissance Orbiter has found evidence of water flow, it is claimed. Using an imaging spectrometer researchers detected the signature of hydrated minerals on slopes where mysterious streaking was seen on the Mars surface. These streaks appear to ebb and flow over time, expanding in warm seasons and contracting in cooler seasons. However, warmer is not so warm as they are talking about temperatures of minus 23 Celsius (which is pretty chilly and not obviously very warm). However, this is where the saltiness comes in, being able to keep water in a liquid below the point of freezing. Hence, it is important to see these intrusions as very salty in order to allow water to flow before freezing. Hydrated salts in the spectro-analysis are therefore an important finding.
You caqn find the same story at various places on the web – go to for example www.space.com/17048-water-on-mars.html …. where we are told of vast deposits of water ice at the poles of Mars. This is thought to melt at the edges during the Martian summer. The new discovery is described as a brine flow rather than a water flow. This suggests ome of the media reports have gone over the top. The NASA spokesman even says that the brine flow does not mean there is life on Mars – or even that it is a likely proposition – but presumably somebody did at some point otherwise we would not have had those news reports. It seems brines such as the flow discovered have a very low actual water content and are not actually too kind for the evolution of life. So what are they getting all excited about?
The answer is provided in two further posts on Phys Org. At http://phys.org/print362759637.html … it seems NASA scientists are really excited by the prospect of water on Mars. However, the water they are looking for is thought to be under the ground – rather than on the surface.
At http://phys.org/print362734701.html … the possibility of water aquifers below the surface of Mars is discussed, the prospect of which opens a new ball game.