Pluto's moon system: survey of the phase space I

The dynamical structure of the phase space of the Pluto--Charon system is studied in the model of the spatial circular restricted three-body problem by using numerical methods. With the newly discovered two small satellites S/2005 P1 and S/2005 P2, the Pluto--Charon system can be considered as the first known binary system in which celestial bodies move in P-type orbits. It is shown that the two satellites are in the stable region of the phase space and their origin by capture is unlikely. Also the large mass parameter allows to regard the satellites as a model of a new class of exoplanets orbiting around stellar binary systems.