A lonely spacecraft is nearing Pluto after a three billion-mile journey lasting almost nine years. Nasa’s New Horizons probe awoke from hibernation on December 6 and is preparing to explore the Solar System’s mysterious ‘ninth planet’. Discovered in 1930, Pluto was until recently described as the planet furthest from the Sun – an average distance of 3.67 billion miles. In 2006 it was reclassified as a newly defined ‘dwarf planet’ within the Kuiper Belt, a swarm of icy objects beyond the realm...
