Asteroids.....not the video game

[Badgemash]

It is amazing, but all coincidence. Keep in mind, there are always objects either passing by, or burning up in our atmosphere. The moon doesn't have an atomosphere - hence the craters.

The one that is flying by, if it hit, would be the equivalent of a 2.5 megaton bomb. We're hit by one about once every 1200 years. The last one that hit was in 1908 - also in Russia. While (I don't believe) it left a crater, it did flatten 830 acres of trees. Pretty impressive.

I'm still holding out hope for the little green men. Or a zombie apacolypse.

We actually get hit all the time, they're usually just pretty small (like marble and baseball sizes). Big ones like what just came down in Russia are more rare, but like you pointed out not super rare. In addition to the Tunguska event in 1908, Russia was also whacked by the Sikhote-Alin meteorite in 1947, which was around 70 tons (I've purchased it for $0.31/gram which tells you how much of it there is lying around). Most of the huge craters you see on the moon are remnants from the Late Heavy Bombardment (4-3.7 bya), since the moon has no active tectonics or atmosphere all the lovely craters were preserved. The moon does still play an important role in protecting the Earth from impactors, but luckily for us most of the really huge stuff has already gone. If 2012 DA14 were to impact Earth, it would leave a similar sized hole to Meteor Crater in AZ, about a mile across. Bad news if you live were it hits, but no where near an extinction level event.

I can't pretend I wouldn't be a little excited for an actual zombocalypse! Yay Walking Dead is back on!