NASA has released a colour image of Pluto's largest moon, Charon, taken by the New Horizons space probe on 14 July 2015. The image is a composite built up from images taken in the blue, red, and infrared parts of the spectrum by the Ralph Multispectral Visual Imaging Camera, processed to accentuate the surface features of the moon.
Discovered in 1978, Charon is the largest moon of Pluto, with a diameter of 1212 km, and 12% of the mass of Pluto itself. This makes it the sixth largest known trans-Neptunian object, after Pluto itself, Eris, Haumea, Makemake and Gonggong, as well as the twelfth largest moon in the Solar System, after Ganymede and Titan (which are both larger than the planet Mercury), Calisto, Io, the Earth's Moon, Europa, Triton, Titania, Rhea, Oberon, and Iapetus.
Pluto and Charon are gravitationally locked, always keeping the same face towards one-another, and orbiting their mutual barycentre every 6.387 days. The two bodies are, on average, 19 591 km apart, although this orbit does vary slightly.
Unlike Pluto, which has a surface largely covered by methane and nitrogen ices, the surface of Charon appears to be covered largely by water ice, with patches of tholins and other hydrocarbons around its north pole. Patches of ammonia and water ice crystals on the surface are thought to indicators of cryovolcanism. The surface of the moon also has a number of large canyons following a southwest-northeast direction.
See also...
Follow Sciency Thoughts on Facebook.
Follow Sciency Thoughts on Twitter.