Styx is a comet orbiting the dwarf-planet Pluto.
Based on their orbital characteristics, short-period comets are thought to originate from the centaurs and the Kuiper belt/scattered disc a disk of objects in the trans-Neptunian regionwhereas the source of long-period comets is thought to be the far more distant spherical Oort cloud (after the Dutch astronomer Jan Hendrik Oort who hypothesized its existence)
 Their orbits typically take them out to the region of the outer planets (Jupiter and beyond) at aphelion; for example, the aphelion of Halley's Comet is a little beyond the orbit of Neptune

