Chapter 8 - Internal structure and cryovolcanism on Trans-Neptunian objects

Abstract

Modeling the evolution and internal structure of large- and mid-size Trans-Neptunian objects (TNOs) is a challenging task, owing to the strong dependence on the thermophysical and structural parameters involved, which are poorly constrained. Thus the outcome of evolutionary tracks for a given object may range from fully pristine to completely differentiated and need to be further constrained by detailed observations of TNOs’ physical and chemical properties. The key question remains, whether knowing surface and bulk properties is sufficient for inferring internal properties and more ambitiously, the evolutionary course of a TNO from formation to present day. Recent models of Charon involve a complex evolution, including the formation of subsurface oceans and past cryovolcanism. This perspective should trigger the development of new comprehensive models, which—combined with new observations—should lead to significant progress in our understanding of how the whole population formed and evolved.