This GIF Shows What Might Be Water Flowing on Mars(theatlantic.com)
theatlantic.com
This GIF Shows What Might Be Water Flowing on Mars
http://www.theatlantic.com/technology/archive/2014/02/this-gif-shows-what-might-be-water-flowing-on-mars/283726/
http://www.theatlantic.com/technology/archive/2014/02/this-gif-shows-what-might-be-water-flowing-on-mars/283726/
There are two reasons one cannot have water flowing on the surface of present-day Mars. One of them is mentioned in the article (temperature too low), but the other reason, for some reason omitted from the article, is that the atmospheric pressure is too low -- liquid water requires a certain amount of atmospheric pressure.
Scientists theorize that there might be very brief flows, a matter of seconds, bursting from an underground water reservoir (where enough pressure might exist to support liquid water) and rapidly sublimating (changing directly from ice or liquid to vapor) as it flows across the surface, which might explain some surface markings that seasonally appear and disappear on the surface.
But the title of the article, and much of its content, is misleading -- we're not going to see "water flowing on Mars" in the way that most readers think of such an event.
A quote from the article: "In any case, these recent studies don't conclusively prove whether there is flowing water on Mars, nor do they begin to answer the big question: could this water support some sort of life?"
This language goes beyond careless -- it's ignorant and irresponsible. If it exists at all, Mars surface water can only last a few seconds. Any search for modern life on Mars will need to go below the surface, where we might find pressurized pockets, at a temperature higher than at the surface, able to sustain liquid water on a continuous basis.