BERLIN (AP) -- A meteor exploded in the sky above Russia on
Friday, causing a shockwave that blew out windows injuring
hundreds of people and sending fragments falling to the ground
in the Ural Mountains. Here's a look at those objects in the
sky: What's the difference between a meteor and a meteorite?
Meteors are pieces of space rock, usually from larger comets or
asteroids, which enter the Earth's atmosphere. Many are burned
up by the heat of the atmosphere, but those that survive and
strike the Earth are called meteorites. They often hit the
ground at tremendous speed -- up to 30,000 kilometers an hour
(18,642 mph) according to the European Space Agency. That
releases a huge amount of force. How common are meteorite
strikes? Experts say smaller strikes happen five to 10 times a
year. Large impacts such as the one Friday in Russia are rarer
but still occur about every five years, according to Addi
Bischoff, a mineralogist at the University of Muenster in
Germany. Most of these strikes happen in uninhabited