books.google.lu - For five decades after its discovery in 1930, the planet Pluto remained an enigma. However, several events during the last two decades have helped to lift the veil of mystery surrounding the ninth planet. The discovery of its satellite, Charon, in 1978 permitted occultation observations that allowed...https://books.google.lu/books/about/Pluto_and_Charon.html?hl=fr&id=VcY7iYJwJZoC&utm_source=gb-gplus-sharePluto and Charon
