Asteroid Hits Earth! How the Doomsday Scenario Would Play Out
et’s start by making 2012 DA14 bigger—though it hardly needs the extra bulk. At its current size, it would produce a blast equivalent to 2.4 megatons, or 180 Hiroshimas, after it entered our atmosphere. A significantly bigger asteroid would produce a significantly bigger blast and there’s no shortage of those cosmic missiles out there. Astronomers estimate there are 2,400 objects in the vicinity of Earth that are at least 0.5 km (0.3 mi) across and 860 of those are a full 1 km (.62 mi.). A 0.5 km rock would produce a 5,000 megaton blast—not to mention a 7.1 Richter-scale shock. Let’s split the difference then, but err on the size of conservatism: Our death rock would be a comparatively modest 100 m, or 330 ft., across.