Mars once hosted lakes, flowing water

Last week, NASA announced they’d spotted occasional signs of flowing water on Mars. These briny flows, discerned from orbit, originated on the steep slopes of valleys or craters at four widely scattered sites in the planet’s southern hemisphere. Now, a comprehensive analysis of images gathered by NASA’s Curiosity rover provides the strongest evidence yet that Mars once was warm and wet enough to have lakes and flowing water year-round and for extended periods of time—possibly for millions of years. The findings hint that the Red Planet once had a climate hospitable enough for microbial life to develop and evolve.