PALS: Fiona Nichols-Fleming (NASM), Understanding Interior Evolution via Surface Tectonics: from Asteroids to Icy Moons

Understanding Interior Evolution via Surface Tectonics: from Asteroids to Icy Moons

Fiona Nichols-Fleming
Postdoctoral Research Geologist
Center for Earth and Planetary Studies
Smithsonian National Air and Space Museum

Abstract: Small bodies and icy moons throughout the Solar System show a wide variety of surface features that can preserve a record of the body’s evolution. To understand the interior evolution of these bodies it is critical to consider both evolutionary models and observed surface features such as tectonic features. In this talk, I will discuss examples for understanding the interior evolution of two very different bodies: asteroid 16 Psyche and Saturn’s moon Dione.

For Psyche, we find that global contraction could provide an independent constraint on the thickness of an outer rocky layer in the case of a differentiated interior and that the moment of inertia could distinguish between two core evolution scenarios. For Dione, we find that the tectonic record contains at least two distinct eras of tectonism which allows us to investigate changes in both the stress state and thermal state over geologic time. Preliminary work finds that the two independent analyses of Dione’s tectonic features are both consistent with the presence of a long-lived subsurface ocean.

Host: Ben Sharkey