A map released yesterday by NASA's Near Earth Object (NEO) Observation Program reveals that small asteroids frequently enter and disintegrate in the Earth's atmosphere with random distribution around the globe. Released to the scientific community, the map visualizes data gathered by U.S. government sensors from 1994 to 2013.
The data indicate that Earth's atmosphere was impacted by small asteroids, resulting in a bolide (or fireball), on 556 separate occasions in a 20-year period. Almost all asteroids of this size disintegrate in the atmosphere and are usually harmless.
The largest impact recorded during this 20-year interval was the Chelyabinsk event (440 000 - 500 000 tons of TNT) recorded over central Russia on February 15, 2013. This small asteroid that exploded in the atmosphere over Russia was about 20 meters in size before it hit the Earth.
