This picture of Pluto and its satellite, Charon, was taken back in 1994 by the Hubble Space Telescope’s Faint Object Camera (operated by the ESA). At the time this picture was taken, Pluto was 4.4 billion kilometers from Earth. Analysis from this image allowed scientists to very accurately measure Pluto’s diameter as 2,320 kilometers and Charon’s diameter to be 1,270 kilometers.