In the spring of 1978, James W. Christy was working at the United States Naval Observatory when he first spotted Charon, Pluto's largest moon, using a relatively modest 12-inch telescope. While analyzing photographic plates taken over several nights, he noticed an unusual elongation in Pluto's image; the elongation suggested the presence of a companion object orbiting Pluto. Further examination confirmed the existence of Charon, which was later understood to be about half the size of Pluto itself. This discovery was pivotal, as it provided crucial insights into the dynamics of the Pluto-Charon system and laid the groundwork for future exploration of the outer solar system. The new moon was named after the mythological ferryman of Hades, reflecting Pluto's own nomenclature that derives from Roman mythology.

Christy’s work did not only contribute to the discovery of Charon but also sparked much interest and ongoing research into the dwarf planet and its moons, particularly in the context of planetary formation and orbital mechanics. The discovery of Charon suggested the possibility that Pluto was less of an isolated body and more of a member of a complex celestial family. Analyzing the gravitational interactions between Pluto and Charon offered scientists valuable information about the density, composition, and formation of both the planet and its moon. Through this event, researchers broadened their understanding of the characteristics of celestial bodies in the Kuiper Belt, advancing scientific inquiry into the nature of these distant objects.