Improbable though it may seem, there’s a real risk that we will someday discover a huge asteroid on a collision course with our planet. The obvious question here is also the important one, i.e. ‘what the hell could we do about it’? Ridiculous movie plots aside, a fair few ideas have been kicked around before, but there’s a new scientific paper just out that suggests the simplest and most effective way to stop a big lump of rock hitting the Earth would be to place another smaller rock in orbit to absorb the blow. Added bonus – we could mine it for all sorts of goodies useful for further space exploration, too.