Naming of moons underworld, and Nix (a respelling of Nyx), mother of Charon, is the goddess of darkness and the night. Kerberos is a giant three-headed dog who guards the entrance to the underworld. The fifth moon is named for the river Styx that forms the boundary between the worlds of the living and the dead. The name of Eris's moon Dysnomia was suggested by its discoverer Michael E. Brown, who also suggested the name of the dwarf planet. The name has two meanings: in mythology Dysnomia (lawlessness) is the daughter of Eris (chaos). However, the name is also an intentional reference to
Greek underworld Greek underworld In mythology, the Greek underworld is an otherworld where souls go after death. The original Greek idea of afterlife is that, at the moment of death, the soul is separated from the corpse, taking on the shape of the former person, and is transported to the entrance of the underworld. The underworld itself—sometimes known as Hades, after its patron god—is described as being either at the outer bounds of the ocean or beneath the depths or ends of the earth. It is considered the dark counterpart to the brightness of Mount Olympus with the kingdom of the dead