Water is a key to the future exploration of Mars and new evidence shows that as the liquid altered the planet’s surface in the past, colossal reservoirs of water ice may still exist below the surface and profoundly impact the red planet today. Steve Saunders, Jet Propulsion Laboratory (JPL) project scientist for the 2001 Mars Odyssey mission, believes spacecraft now orbiting the planet are painting a very intriguing, albeit complex, picture of past and present Mars. Saunders presented the Committee on Space Research (COSPAR) interdisciplinary lecture this morning, here at the World Space Congress.