48708 24.9 Hydra 2005 36 .391 64749 38 S/2011 P4 2011 20 approx ? 59000 32.1 S/2012 P5 2012 10--25 ? 42000+/-2000 20.2+/-0.1 --------------------------------------------------------------------------------------- Because Pluto and Charon are mutually tidally locked (see Wikipedia: Tidal locking: Occurrence: Moons ), their orbital periods and rotation periods are all the same (i.e., 6.3872