Knowra Moons of Pluto Moons of Pluto The five known natural satellites of Pluto are Charon, Styx, Nix, Kerberos, and Hydra. Their unusually compact, synchronized system formed around the dwarf planet and was closely examined by New Horizons.
Charon : Pluto’s largest moon, nearly half its diameter and massive enough to make Pluto and Charon a binary dwarf-planet system. Its size and mutual tidal locking dominate the dynamics of the entire satellite system.
Giant-impact hypothesis : The hypothesis that a large collision produced a planet's debris disk and, from it, one or more moons. A collision between Pluto and another body is the leading explanation for the system’s origin.
Styx : The smallest known moon of Pluto, discovered in 2012 and named for the river of the underworld in Greek mythology. Styx is the innermost and least massive of Pluto’s four small moons.
Jupiter's moons : The natural satellites orbiting Jupiter, including the four large Galilean moons and many smaller bodies. Jupiter’s much larger satellite system contrasts with Pluto’s compact, low-mass family.
Orbital resonance : A relationship in which orbiting bodies exert regular gravitational influence because their orbital periods form simple ratios. Styx, Nix, Kerberos, and Hydra occupy a near-resonant chain around Pluto and Charon.
Circumbinary disk : A disk of gas or debris orbiting around two gravitationally bound central bodies. Debris orbiting the Pluto–Charon pair could have assembled the four smaller moons.
Nix : A small, irregular moon of Pluto discovered in 2005 and imaged by the New Horizons spacecraft. Its surface markings and rapid, chaotic rotation distinguish one of the system’s best-observed small moons.
Earth's Moon : Earth’s only permanent natural satellite, a large body in a nearly circular orbit around its planet. Earth has one dominant moon, unlike Pluto’s multiple moons orbiting a binary central pair.
Tidal locking : A state in which a body's rotation period matches its orbital period, keeping the same hemisphere facing its partner. Pluto and Charon are mutually tidally locked, while the smaller moons rotate unusually rapidly.
Pluto–Charon formation : The proposed formation of Pluto and Charon through a collision between large objects in the early Kuiper belt. The event that formed Charon may also have supplied material for the outer satellites.
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