Powering the Galilean Satellites with Moon-Moon Tides

TL;DR

This paper explores how moon-moon tidal interactions among the Galilean satellites can generate significant internal heating, providing new insights into their subsurface oceans and potential habitability.

Contribution

It is the first study to analyze moon-moon tides in the Galilean system and demonstrates their potential to cause substantial heating and constrain subsurface ocean properties.

Findings

Moon-moon tides can induce high-frequency resonant tidal waves.

Tidal heating from moon-moon interactions can surpass other sources.

Results can help constrain subsurface ocean thickness.

Abstract

There is compelling evidence for subsurface water oceans among the three outer Galilean satellites, and evidence for an internal magma ocean in the innermost moon, Io. Tidal forces from Jupiter periodically deform these bodies, causing heating and deformation that, if measured, can probe their interior structures. In addition to Jupiter-raised tides, each moon also raises tides on the others. We investigate moon-moon tides for the first time in the Galilean moons, and show that they can cause significant heating through the excitation of high-frequency resonant tidal waves in their subsurface oceans. The heating occurs both in the crust and ocean, and can exceed that of other tidal sources and radiogenic decay if the ocean is inviscid enough. The resulting tidal deformation can be used to constrain subsurface ocean thickness. Our understanding of the thermal-orbital evolution and habitability of the Jovian system may be fundamentally altered as a result.