KLD4
Keynote (OPS): Unveiling the Interior Structure of Icy Satellites: Open Questions at the Dawn of a New Age of Exploration
Co-organized by OPS
Abstract
Icy satellites throughout the outer Solar System - from the Galilean moons to Titan, Enceladus, and the moons of Uranus - have emerged as some of the most compelling targets in planetary science. Thanks to the Galileo and Cassini missions, some of the mysteries surrounding their interior structures have been revealed, including the potential existence of subsurface liquid water. Yet fundamental questions remain open: the existence of global subsurface oceans, the thickness of the outer ice shells, the composition of the putative oceans, the nature of water-rock interactions, and the role of tidal dissipation in sustaining the oceans over geological time.
The surprising discoveries and the questions that stemmed from them ignited the next generation of missions to icy satellites, and the next two decades will bring transformative changes in our understanding of icy satellite interiors. NASA's Europa Clipper and ESA's JUICE mission will provide gravity, magnetic, and compositional measurements of the Jovian icy moons that will yield unprecedented knowledge of the interiors of Europa, Ganymede, and Callisto. NASA's Dragonfly mission will deliver in-situ exploration of Titan's surface through the first rotorcraft mission to an icy satellite. Looking further ahead, a mission to Enceladus, currently under study by ESA as a candidate L4 mission, promises to directly sample plume material and probe the moon's active ocean-rock interface, building on the legacy of Cassini.
In this talk, I will review the current state of knowledge on icy satellite interiors based on past missions, highlight the geophysical techniques used to probe them, and discuss how the coming generation of missions will reshape our understanding of ocean worlds and their potential habitability in the decades ahead.