Planetary scientist Dr. Robert Pappalardo of the Jet Propulsion Laboratory discusses the exploration of Europa and what that moon has taught us about ocean worlds in the outer solar system. As the project scientist for NASA’s Europa Clipper mission, Pappalardo also discussed the future mission to Europa. This was the second presentation in the Lunar and Planetary Institute’s 2017–2018 Cosmic Exploration Speaker Series, “Diving into Ocean Worlds.”