Research Update: polar wander on Enceladus

Enceladus is a fascinating moon. It is a tiny ice ball, ~500 km across, but has evidence of geologic activity from ridges from where water ice is actively being spewed out of Enceladus as plumes, indicating the existence of a subsurface liquid water ocean beneath its ice shell. Furthermore, samples of Saturn’s E-ring, a part of Saturn’s rings created by icy particles from the Enceladus plumes, reveal chemical evidence of hydrothermal activity at its ocean floor, which could create habitats for potential extraterrestrial life.

Schematic showing current view of the interior structure of Enceladus with its subsurface liquid water ocean and southern hemisphere plumes illustrated. Original image credit: NASA.

Although Enceladus is a common astrobiological target, our ability to predict its potential habitability is limited by the fact that it is not clear what is driving the current geologic activity on Enceladus.

To explore this topic, I am working with my collaborator to create geologic maps of Enceladus and computer models that predict tidal stress to investigate the role that polar wander stress could have played in the formation of Enceladus’s active geologic features. In this update, I show some of the preliminary results of my part of the project. This project is still ongoing but model results so far suggest that true polar wander could play a role in Enceladus’s surface geology and very similar geology on Uranus’s moon Miranda. This project adds to our understanding how icy moons work and the number of possible habitable ocean worlds in the solar system and beyond.