If NASA turns out to be wrong about this one not hitting the planet -- and they won't be -- then Asteroid 2012 DA14 would not destroy the world in any case, Yeomans said.

An asteroid made of metal that was about the same size collided with Earth 50,000 years ago, creating the mile wide "Meteor Crater" in Arizona and obliterating everything for 50 miles around, he said.

2012 DA14 is likely made of stone, which would do much less damage.

In 1908 a similar type asteroid entered the atmosphere and exploded over Tunguska, Russia, leveling trees over an area of 820 square miles -- about two thirds the size of Rhode Island.

Not Earth shattering, but you still wouldn't want to live nearby.