A Behind the Scenes Look at the Pluto System

Nature June Cover

Nature magazine coverThe June 2015 cover of Nature features an illustration of the mechanism at work behind the scenes in the Pluto system: 'gear ratios' are such that the observed orbital ratios of 1:3:4:5:6 are enforced. With NASA’s New Horizons probe fast approaching Pluto for its flyby on 14 July, Mark Showalter and Douglas Hamilton present new results from the Pluto system and offer some predictions about what the spacecraft might observe. Pluto’s four small moons — Styx, Nix, Kerberos and Hydra — follow near-circular, near-equatorial orbits around the central ‘binary planet’ comprising Pluto and its large moon, Charon. In an analysis of Hubble Space Telescope images, Showalter and Hamilton demonstrate that Styx, Nix and Hydra are tied together by a three-body resonance. Perturbations by the other bodies inject chaos into this otherwise stable configuration so that Nix and Hydra rotate chaotically, driven by the large torques of the Pluto–Charon binary. Nix and Hydra have bright surfaces similar to that of Charon. Kerberos may be much darker. Cover art: Mark A. Garlick/markgarlick.com.

Read the Mark Showalter, Douglas Hamilton article Resonant interactions and chaotic rotation of Pluto's small moons (PDF download)

Read the Nature overview piece at http://www.nature.com/news/pluto-s-moons-move-in-synchrony-1.17681?WT.ec...