How noble of them to make a bet they can't possibly loose
There is certainly ice on Mars, and even the remote possibility of small pockets of liquid water under the surface. But there can be absolutely no liquid water on the surface!!!!!!!!!!!!!!!
Because the atmosphere on Mars is so thin, H20 on Mars goes straight from solid to gas, without passing through a liquid phase. In other words, its boiling point is the same tempurature as its melting point!
Only in some of the deepest pockets of Mars, such as the Hellas Basin, is the air pressure high enough for pure water to exist in a liquid form over even a few degrees of temperature.
However, there is some possibility of a 'briny solution'...a water thats been super-saturated with salts and minerals...existing as a liquid for short periods of time in the thin Martian air. This is what some of the more optimisted scientists are hoping to find in Gusev Crater.