Sky fall: Meteorites strike Earth every few months

Harris, of the German Aerospace Center, says some meteorites are also believed to carry organic material and may have influenced the development of life on Earth.

Q: What would happen if a meteorite hit a major city?

A: Scientists hope never to find out, but they have been trying to prepare for such an event anyway. Von Weyhe, the European Space Agency spokesman, says experts from Europe, the U.S. and Russia are already discussing how to spot potential threats sooner and avert them. But don't expect a Hollywood-style mission to fly a nuclear bomb into space and blow up the asteroid, like the movie "Armageddon."

"It's a global challenge and we need to find a solution together," he said. "But one thing's for sure, the Bruce Willis 'Armageddon' method won't work."