The presence of such a large amount of water ice under Mars’s surface is very surprising. Especially so close to the surface!” says Gerhard Schwehm, Head of the Planetary Missions Division at ESA. The team working on ESA’s Mars Express, the next mission to the Red Planet, is thrilled by NASA’s Mars Odyssey detection of hydrogen-rich layers under the Martian surface. This hydrogen indicates the presence of water ice in the top surface of the Martian soil in a large region surrounding the planet’s south pole. ESA’s Mars Express, ready for launching in June 2003, has the tools for searching much deeper below the surface, down to a few kilometres. “Mars Express will give a more global picture of where the water is and how deep,” says Patrick Martin, ESA deputy project scientist for the Mars Express mission.