Dwarf planet that are more massive than Eris are the Moon, the four Galilean moons of Jupiter (Io, Europa, Ganymede, and Callisto), one moon of Saturn (Titan), and one moon of Neptune (Triton). The others are six moons of Saturn (Mimas, Enceladus, Tethys, Dione, Rhea, and Iapetus), five moons of Uranus (Miranda, Ariel, Umbriel, Titania, and Oberon), and one moon of Pluto (Charon). There are additional possibilities among TNOs, including Dysnomia orbiting Eris. Alan Stern calls these moons "satellite planets", one of three categories of planet together with dwarf planets and classical planets. The term "planemo" ("planetary-mass object") covers all three. In
Clearing the neighbourhood its natural satellites or those otherwise under its gravitational influence. A large body that meets the other criteria for a planet but has not cleared its neighbourhood is classified as a dwarf planet. This includes Pluto, which is constrained in its orbit by the gravity of Neptune and shares its orbital neighbourhood with Kuiper belt objects. The IAU's definition does not attach specific numbers or equations to this term, but all the planets have cleared their neighbourhoods to a much greater extent (by orders of magnitude) than any dwarf planet, or any candidate for dwarf planet. The phrase may be