How Would We Save the Planet from a Killer Asteroid?

We don't need to be scared of everything that falls from space. In fact, literal tons of space rocks rain down daily, though that's mostly in the form of minuscule dust grains. But every 100 million years or so, catastrophe strikes in the form of a rock spanning miles.The last one killed not just the dinosaurs, but three-quarters of all life on Earth. The effects on humans could be equally devastating — bomb shelters wouldn't cut it in the face of such an event.Not when the shake