Listen in on a discussion between a panel of experts, including Heidi Hammel, Executive Vice President of the Association of Universities for Research in Astronomy; Tess Russo, a hydrologist at Pennsylvania State University; Ellen Stofan, planetary geologist and Chief Scientist of NASA; Kathryn Sullivan, a geologist at NOAA; and Charles Wald, a retired general from the U.S. Air Force. Host and moderator Neil deGrasse Tyson, Frederick P. Rose Director of the Hayden Planetarium, leads this lively conversation on the past, present, and future of water. The 2015 Isaac Asimov Memorial Debate took place at the Museum on April 28, 2015.