Every year U.S. military satellites detect about a dozen small asteroid explosions in the atmosphere. These asteroids, measuring several feet across, pose almost no direct threat. However, observers on the ground occasionally mistake them for nuclear or conventional weapons attacks, raising the danger of a misguided military retaliation.
Some of the larger fragments from these explosions land as meteorites. Several meteorite falls were reported during just a four-year period earlier this century, including: a shower of dozens of pebble-sized meteorites in Canada's Yukon Territory, more than 400 fragments falling in rural Lesotho, Africa, and a shower of meteorites large enough to damage six houses and three cars in a Chicago suburb.
These meteorites explode high in the atmosphere. While the explosion may be visible from the ground, it poses no direct threat. Meteorite fragments may make holes in buildings or other objects on the ground.
Topic: Earth Science
Keywords: Asteroids--Collisions with Earth, Astrogeology, Astrophysics, Collisions (Astrophysics), Meteorites, Natural disasters, Near-Earth asteroids