Presentation #501.01 in the session “KBOs and Multiples”.
The initial orbit and spins of the Pluto-Charon binary may have substantially differed from those observed today. It is often assumed that tides raised on Charon dominate the evolution towards the present configuration, in order to keep a moderate eccentricity in the system. Nevertheless, that is not necessarily the case when we take into account a 3D model that also includes the Sun. Indeed, for a high initial obliquity for Pluto or a spin-orbit capture of Charon’s rotation, the binary eccentricity is damped very efficiently. On the other hand, for small initial obliquity for Pluto, the presence of the Sun triggers Lidov-Kozai cycles when the eccentricity grows to high values, which also prevents Charon from escaping.