Mars has seasonal rivers of flowing water!

Note the verb “has” rather than “had”, as in liquid water is a current feature on present-day Mars. In other words, this is not from the distant past — the water is flowing now. 

What appeared to be a dry void of red-orange rock is wetter than previously thought.

Liquid water is the key to terrestrial life as we know it, so the announcement isn’t just a major hydrological discovery, but goes a long way toward supporting the possibility of — cue David Bowie — life on Mars. The findings were reported today in the journal Nature Geoscience.

It is the briny-ness of the water that keeps it from freezing:

http://popularmechanics.com/space/moon-mars/news/a17498/there-is-water-flowing-on-mars-as-we-speak/

http://wired.com/2015/09/nasa-salty-liquid-water-on-mars/12

750 Reddit comments:

https://reddit.com/r/space/comments/3mjrdt/nasa_to_confirm_active_briny_water_flows_on_mars/