Image 1 Caption: The gravitationally-bound Pluto-Charon system.

Features:

1. The film or animation (based on actual images) is highly pixelated.

2. The Pluto-Charon system is a subsystem of the Pluto system which also includes 4 other small moons of Pluto: Hydra, Kerberos, Nix, and Styx.

3. The small moons collectively have a mass that is ∼ 10**(-5) of the mass the Pluto-Charon system (see Wikipedia: Moons of Pluto: List). Thus, they are negligible for the motions of the Pluto-Charon system to high order of approximation. The Pluto-Charon system is nearly an exact gavitational two-body system.

   We neglect the small moons in the rest of this explication of the Pluto-Charon system.

4. Pluto and Charon have nearly circular orbits about the center of mass of Pluto-Charon system.

   To 1st-order, the center of mass defines an inertial frame for the Pluto-Charon system and the Pluto system as a whole.

5. The main orbital elements of the Pluto-Charon system are: orbital period p = 6.3872304(11) days, eccentricity e = 0.00, average orbital velocity 0.21 km/s, Pluto mean orbital radius 2035 km = 1.714 Pluto radii (Pluto mean radius = 1187 km), Charon 17536 km = 14.77 Pluto radii, mean orbital radius of true relative orbit (i.e., mean separation) 19571 km = 16.49 Pluto radii (see Wikipedia: Charon).

6. Pluto and Charon are mutually tidally locked (see Wikipedia: Charon: Orbit). Thus, each one always turns the same side to the other.

   If you are at a given location on the side of Pluto/Charon facing Charon/Pluto is always in the sky at the same position relative to the ground for your location. If you are on the other side of Pluto/Charon, you never see Charon/Pluto.

   

7. Image 2 Caption: "An animation showing an oblique view (more exactly a view at high inclination) of the orbits of Pluto and Charon. Note Pluto and Charon are mutually tidally locked to each other, and so always turn the same side to the other. Charon is massive enough that the center of mass of the Pluto system (which includes 4 other small moons which have little effect on the location of the center of mass) lies outside of Pluto, and thus Pluto and Charon are sometimes considered to be a binary system." (Somewhat edited.)

Images

1. Credit/Permission: NASA / Johns Hopkins University Applied Physics Laboratory (JHU-APL) / Southwest Research Institute (SWRI), 2015 (uploaded to Wikimedia Commons by User:Njardarlogar, 2015) / Public domain.
   Image link: Wikimedia Commons: File:Barycentric view of Pluto and Charon 29 May-3 June by Ralph in near-true colours.gif.
   
2. Credit/Permission: © Stephanie Hoover (AKA User:StephHoover), 2013 / CC BY-SA 1.0.
   Image link: Wikimedia Commons: File:Pluto-Charon System.gif.