LPL Colloquium: Dr. Kelsi Singer
Craters and Cryovolcanoes – Comparisons Across the Outer Solar System
Dr. Kelsi Singer
Southwest Research Institute
Craters are a ubiquitous feature of most planetary surfaces but can also be informative by their absence. I will present two projects inspired by New Horizons data: 1) the cratered surfaces of Pluto and Charon and what they imply about the Kuiper belt populations that formed them and 2) the potential cryovolcanic resurfacing on Pluto and Charon compared to other examples in the outer solar system.
The New Horizons spacecraft observed impact craters on Pluto and its moons, providing the first data from planetary surfaces embedded in the Kuiper belt and a view of KBOs smaller than can be directly observed by telescopes. The Kuiper belt size-frequency distribution does not look like the asteroid belt at these small sizes and is not consistent with predicted collisional equilibrium slopes. Signs of cryovolcanic resurfacing are apparent on Pluto and Charon in the form of both smooth terrains and hummocky/massive topographic features. On Charon, the volcanism appears to have primarily occurred early in its history, but that also left a unique surface to measure craters on—enabling the above cratering results. Pluto has several examples of more recent activity (with few-to-no superimposed craters), the most prominent being two enormous domes. The informally named Wright Mons stands ~4 km high and the main mound spans ~150 km. Piccard Mons is ~7 km high and 225 km wide. Each potential example of cryovolcanism found in the outer solar system is unique, and Pluto and Charon’s features expand the information we have to understand this enigmatic process.