Moon of Pluto
Diameter: 1208 km
Distance: 17536 km (mean)
Period: 6.3872 days
Eccentricity: 0.0022
Inclination: 0.001°
Magnitude: 17.3

Discovered in 1978, this largest moon of Pluto's is almost half the size of Pluto. It is so big Pluto and Charon are sometimes referred to as a double planet system. Revolving about each other every 6.387 days, the center of mass of the system lies outside either body.