In Pixar’s robot love story WALL-E, the Earth is surrounded by a dense field of orbiting junk. (Incidentally, you know you’re a geek when you’re the only one laughing in the cinema because you recognise one of the satellites that WALL-E has to brush out of his way as Sputnik 1.) But while things today aren’t quite as bad as depicted in WALL-E, space debris is still a big problem, as can be seen on a real plot from NASA of the junk orbiting overhead.

