Mars has likely never been sufficiently warm for liquid water to have flowed on the surface for extended periods of time.
So the super giant canyon on mars was not made by erosion over a long period of time?
So if it was made in a relatively SHORT period of time,
where did that tremendous volume of water come from?
Where did it go?
I have a very strong feeling that Mars is going to teach us a whole boatload of geological tricks that we've never seen on planet Earth!