Enceladus is among the most intriguing bodies in the solar system due to its astrobiological potential. Determining the extent and duration of habitability (i.e., sustained habitability) at Enceladus requires characterizing its interior properties as well as the level and distribution of tidal heating. Inferring the intensity of geophysical activity in the core has direct implications for understanding the potential for hydrothermal activity and the supply of chemical species important for habitability to the ocean. We build a statistical framework using an MCMC approach to constrain the interior structure based on currently available estimates of libration, shape, heat flux, and total mass. We use this framework to examine the extent to which geodetic measurements can improve our understanding of the interior structure, with an emphasis on determining the partitioning of tidal dissipation between the shell and the core. We quantify plausible ranges of gravitational (k2) and displacement (h2 and l2) tidal Love numbers consistent with existing observations. We demonstrate that measuring the amplitude and phase of k2 alone can only constrain the total tidally dissipated energy, but not its radial distribution. However, measuring the amplitude and phase of h2 or l2 facilitates determining the extent of tidal dissipation in the shell and the core. We provide the precisions required for measuring k2, h2, and/or l2 that enable distinguishing between the two main scenarios of tidal heating, i.e., in the shell versus the core. We also briefly explore the effect of the structural heterogeneities of the shell on the tidal response. Lastly, we evaluate the efficacy of a suite of future geodetic measurements to constrain key interior properties essential to understand the present-day (i.e., instantaneous) and long-term (sustained) habitability at Enceladus.
Bagheri et al. (Tue,) studied this question.