Quote Originally Posted by Animeniax
Just because water doesn't flow on Mars, that doesn't imply that there's no water on Mars. Remember the water-filled caves of Arrakis, also known as Dune? They just need the Messiah to come and reveal the water on Mars, much as Paul Muad'dib brought rain to Arrakis.

So all those rivulets and ravines were made by Shai-hulud?