During the first half of the 20th century, we focused our imaginations on cosmological disasters. Billions of years from now, the sun will explode, vaporizing the Earth in a ruthless inferno. Or perhaps a swarm of asteroids would bombard our cities and crash into our oceans, resulting in a series of megatsunamis. Other scenarios included one where the Earth's surface would shrink so tightly, that its core would explode with the pressure, turning our beloved planet into just another asteroid belt. The most bizarre theory was that a rogue star would cross into our solar system, swallowing our planet within streams of deadly solar rays.