Tidal evolution of the Pluto-Charon binary

Abstract

A giant collision is believed to be at the origin of the Pluto-Charon system. As a result, the initial orbit and spins after impact may have substantially differed from those observed today. More precisely, the distance at periapse may have been shorter, subsequently expanding to its current separation by tides raised simultaneously on the two bodies. Here we provide a general 3D model to study the tidal evolution of a binary composed of two triaxial bodies orbiting a central star. We apply this model to the Pluto-Charon binary, and notice some interesting constraints on the initial system. We observe that when the eccentricity evolves to high values, the presence of the Sun prevents Charon from escaping because of Lidov-Kozai cycles. However, for a high initial obliquity for Pluto or a spin-orbit capture of Charon's rotation, the binary eccentricity is damped very efficiently. As a result, the system can maintain a moderate eccentricity throughout its evolution, even for strong tidal dissipation on Pluto.

14 pages, 10 figures

References in corpus (8)

• Deformation and tidal evolution of close-in planets and satellites using a Maxwell viscoelastic rheology
• Mercury's capture into the 3/2 spin-orbit resonance including the effect of core-mantle friction
• On the equilibrium figure of close-in planets and satellites
• Formation of Kuiper Belt Binaries
• Impact cratering on Mercury: consequences for the spin evolution
• On the Stability of Extrasolar Planetary Systems and other Closely Orbiting Pairs
• The Wide-Binary Origin of The Pluto-Charon System
• A Pluto-Charon Concerto: An Impact on Charon as the Origin of the Small Satellites

Cited by in corpus (1)

• A Pluto--Charon Concerto II. Formation of a Circumbinary Disk of Debris After the Giant Impact