Charon is a medium-sized body, approximately 750 miles (1,207 kilometers) wide, located in the Kuiper Belt—a ring of icy debris, comets, and dwarf planets, also called trans-Neptunian objects (TNOs), at the edge of the solar system. Unlike many larger Kuiper Belt objects, Charon’s surface is not covered in volatile ices like methane, allowing scientists to gain valuable insight into the influence of sunlight on cratering these distant bodies. Furthermore, Charon is the only medium-sized TNO for which geological mapping is available. This was made possible thanks to data collected by NASA’s New Horizons spacecraft, which visited the Pluto system about a decade ago.