Four small moons, Styx, Nix, Kerberos and Hydra, orbit the central binary planet comprising Pluto and Charon. Showalter and Hamilton (Nature 522, 45-49, 2015) analyzed Hubble Space Telescope (HST) data from 2010-2012 to explore some of the dynamical consequences of orbiting a binary planet. They noted evidence for a chaotic rotation of Nix and Hydra, and identified a possible three-body resonance between Styx, Nix and Hydra. We revisit the dynamics of the outer moons based on the latest data from the New Horizons flyby. As the spacecraft approached Pluto, the LORRI camera regularly imaged the moons over a period of ~100 days. This data set will make it possible to derive light curves and rotation rates unambiguously, something that has not been possible from the sparsely sampled HST data. It also extends the time baseline of the orbit determinations by several years, providing a more precise test of the proposed orbital resonances. We will discuss the latest measurements and their dynamical implications for the evolution of the Pluto system. This work was supported by NASA's New Horizons project.
AAS/Division for Planetary Sciences Meeting Abstracts #47
- Pub Date:
- November 2015