Charon Information Page

The largest of Pluto's five moons, Charon, was discovered in June 1978 by James Christy and Robert Harrington at the U.S. Naval Observatory in Flagstaff, Arizona―only about six miles from where Pluto itself was discovered at Lowell Observatory. At half the size of Pluto, Charon is the largest of Pluto's moons and the largest known satellite relative to its parent body. Pluto-Charon is our solar system's only known double planetary system. The same surfaces of Charon and Pluto always face each other, a phenomenon called mutual tidal locking. Charon orbits Pluto every 6.4 Earth days.

urn:nasa:pds:context:target:satellite.134340_pluto.charon

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