Circa 15 years ago Mars Express embarked on an extraordinary journey, probing the secrets of the Martian surface. Its spotlight was on the enigmatic Medusifase formation, a geological marvel, spanning hundreds of kilometers and soaring kilometers high. Initially studied for its extensive deposits this formation has remained an intriguing mystery. Today the shroud over the Medusifase formation begins to lift, courtesy of recent research. Thomas Waters, a leading scientist from the Smithsonian Institution, reveals new insights. The Mars Express' Marseille Sradar has unearthed deposits up to 3.7 kilometers thick. Interestingly, these radar signals are akin to those from Mars' polar caps suggesting the presence of layered ice. The implications are staggering. The ice within the Medusifase formation, if melted, could swath Mars in a water layer measuring between 1.5 to 2.7 meters deep. This discovery points to the largest water reservoir in this Martian region.