Tidal dissipation in satellites affects their orbital and rotational evolution and their ability to maintain subsurface oceans. However, a satellite’s dissipation rate, parameterized by k₂/Q, is hard to measure and is only known for the Moon and Io. Here we show that Titan’s measured departure from its expected rotation state can be used to infer k₂/Q and its boundary layer dissipation parameter K/C_s. Over the likely range of ocean and ice shell thicknesses, we infer a K/C_s of 6.3x10^-14 s^-1 – 2.4x10^-10 s^-1, a k₂/Q of 0.058–0.12, and a minimum dissipation factor Q≈5. Titan’s dissipation parameters are one to two orders of magnitude larger than the Moon’s and suggest an interior with a low effective viscosity. Titan’s dissipation rate implies that its orbital eccentricity and inclination are damping rapidly, consistent with an excitation within the last ~350 Myr. Titan’s predicted tidal response could be measured by the forthcoming Dragonfly lander, and JUICE could use our approach to determine Ganymede’s k₂/Q.

This document contains all of the Python code to reproduce the results, figures, and tables in Downey & Nimmo (2024). At the end of the file are the specific commands to call to create each figure and to output a number that is used in the text. No collected data were used in this work.