World
Charon
Charon is Pluto’s biggest moon, half Pluto’s size; the two always turn the same faces to each other, about 1 212 km across.
Where it is right now is on the live 3D map.
Key facts
- Diameter
- 1 212 km
- Goes round
- Pluto
See it from here
Barely: Charon is magnitude 16.8, 13 000 times fainter than the faintest star you can see, and so close to Pluto that amateurs split the pair in 2008 by photographing them through a 14-inch telescope.
How the map draws it
Its colours come from New Horizons’ red and blue pictures, with green taken halfway between them and the colour made half as strong again; the parts photographed only in black and white are given the map’s average colour · the far south was in winter darkness when New Horizons passed in 2015 and is left plain, not guessed · lit as a camera exposed for its own sunlight would show it · seen from far off it is a light at its computed brightness: the glow is how a camera records a point too bright to resolve.