What evidence supports theories that water once flowed on Mars?
Orbiting probes around send photographs of some martian slopes where streaks were found in hot seasons..Dried river beds wre seen in many photographs.
They doubt that it is flow of liquid water with some perchlorites.
Previously also traces of water were found on martian surface..
Surface shows dried river beds. THe pattern in surface shows flow Marks.It is though that millions years before Mars have a thick atmosphere and there was liquid water at that time..