Pluto gets jiggy with its biggest moon, Charon, in an amazing series of pictures just released by NASA's New Horizons mission. The time-lapse images from New Horizons' Long Range Reconnaissance Imager, or LORRI, show Charon circling the dwarf planet as seen from a distance of more than 262 million miles (422 million kilometers) during the July 19-24 time frame. The funny thing is that Pluto weaves back and forth in time with Charon's orbital dance.
What's going on? Charon's mass is roughly a tenth of Pluto's, which gives its enough gravitational pull to have a noticeable effect on Pluto's position. The center of gravity for the two bodies, also known as the barycenter, is actually between them. That has led some astronomers to suggest that Pluto and Charon should be considered double dwarf planets, with four smaller moons thrown into the bargain. Over the next year, New Horizons' view of the planetary pas de deux will get much better — climaxing in a close flyby on July 14, 2015.
— Alan Boyle, NBC News