geological process could be generating the mountainous landscape. The structures, together with the smoothness of Pluto’s surface, suggest that geological activity is taking place and smoothing over depressions caused by asteroid impacts. Scientists believe this “paving” process could be the result of internal heat that softens rock and ice or from snowfalls that cover the surface. For scale, the images are so detailed that, if the craft were flying over London, we would be able to pick out the runways at Heathrow airport. The distance to Pluto – 5bn km – means it takes New Horizons hours to send back a single picture and it will take 16 months to send all the data it has accumulated during the fly-by. The team also announced that the heart-shaped feature visible on Pluto will now be known as the Tombaugh Regio, in honour of Clyde Tombaugh, who discovered the dwarf planet in 1930. The new view of Charon reveals a varied, complex terrain. An area of cliffs and troughs stretching about 1,000km suggests widespread fracturing of Charon’s surface, which could also be the result of geological activity. The image also shows a dramatic canyon estimated to be 7 to 9km deep. Cathy Olkin, a mission scientist, said: “Charon just blew our socks off when we had the new image today. The team has just been abuzz. There is so much interesting science in this one image