While recent discoveries appear to show the existence of large amounts of surface water in the distinct past on the planet, this new paper in Science suggests water may still be there. It was conclusion reached with the help of the Mars Advanced Radar for Subsurface and Ionospheric Sounding or MARSIS project. Imagine even that prospect for possible life or even supporting a Mars colony.
The discovery may be bitter sweet for colleagues for the designer of MARSIS and believed that its signals were showing a subglacial lake. His name is Giovanni Picardi and he passed away in 2015. Picardi now may have his vindication.