... Credit Copyright: A. Stern ( SwRI ), M. Buie ( Lowell Observatory ), NASA , ESA , Explanation: No spacecraft from Earth has yet explored Pluto but astronomers have found ways of mapping its surface . A stunning map of this distant, diminutive planet , the first based on direct images, was revealed late last week in a Hubble Space Telescope press release . ... The map is based on Hubble images made when Pluto was a mere 3 billion miles distant. ... Publications with keywords: Pluto - HST . ...