Map Projection of Charon (IMAGE) International Astronomical Union Caption Map projection of Charon, the largest of Pluto's five moons, annotated with its first set of official feature names. With a diameter of about 1,215 km, the France-sized moon is one of largest known objects in the Kuiper Belt, the region of icy, rocky bodies beyond Neptune. Credit NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.