Exploring the Satellites of the Outer Planets: Insights into Planetary Processes and Planning Future Missions

Progressive exploration from the Pioneer and Voyager flyby missions to the Galileo and Cassini orbiters at Jupiter and Saturn, respectively, revealed myriad surprises about the satellites of our outer solar system, including the extent of active geologic processes and the surprisingly common presence of interior oceans. The diverse array of satellites in outer-planet systems offers valuable opportunities for comparative planetology studies of planetary processes. And ocean worlds in particular give us insights into fundamental questions about planetary habitability and the origins of life. The data, discoveries, and new questions raised by previous missions, in turn, provide the foundation for building the next generation of spacecraft and mission teams to take the next steps in exploring some of these worlds — e.g., Europa Clipper, Jupiter Icy Moons Explorer (JUICE), and Dragonfly — as well as opportunities to expand our horizons at other destinations in the future