Last time a stray planetoid the size of Mars smashed into Earth, it scattered our planet's young crust into space, where gravity glued those particles into the Moon. This time, it would be all hellfire and brimstone with no survivors left.
With comets hurtling towards earth, deadly GMO's and the threat of nuclear weapons dropping at any moment, it's amazing that we've managed to make it to 2015. Discover the 10 times we've come perilously close to destroying the world.