The past decade has seen remarkable progress in exobiology, and the coming century holds even greater promise.  Within the next twenty years, we will have catalogs of hundreds if not thousands of planets around other stars, we will establish a kind of Mars internet with regular video streaming to Earth, and we will have begun to explore the likely ocean underneath the icy crust of Jupiter’s moon Europa. How certain is it that Europa really harbors the solar system's second ocean, and what are the prospects for life there? How should we go about exploring this world, and looking for life? From the Series:Distinguished Leaders in Science