John Smith sat on the couch staring blankly at the television, barely registering what was on the screen. His mind was elsewhere, replaying the news report he had just watched in a state of disbelief. An asteroid was hurtling towards Earth, set to collide with the planet in exactly one week. The impact was projected to be catastrophic, with the asteroid estimated to be several miles wide. It would strike the atmosphere with the force of over a billion atomic bombs, obliterating everything within thousands of miles. Global climate effects would render the surface uninhabitable for the foreseeable future.