Crustal Failure on Icy Moons from a Strong Tidal Encounter

TL;DR

This paper models how close tidal encounters can cause crustal failure and fractures on icy moons, potentially explaining features like graben complexes and chasmata observed on moons such as Dione, Tethys, Ariel, and Charon.

Contribution

It introduces a mass spring model within an N-body simulation to study surface deformation and brittle failure caused by tidal encounters on icy moons.

Findings

Tidal encounters can induce significant surface stress leading to fractures.

Fractures can extend over a large fraction of the moon's radius.

Strong tidal encounters may explain geological features like graben complexes.

Abstract

Close tidal encounters among large planetesimals and moons should have been more common than grazing or normal impacts. Using a mass spring model within an N-body simulation, we simulate the deformation of the surface of an elastic spherical body caused by a close parabolic tidal encounter with a body that has similar mass as that of the primary body. Such an encounter can induce sufficient stress on the surface to cause brittle failure of an icy crust and simulated fractures can extend a large fraction of the radius of body. Strong tidal encounters may be responsible for the formation of long graben complexes and chasmata in ancient terrain of icy moons such as Dione, Tethys, Ariel and Charon.