Asteroid Flyby

An asteroid roughly 115 feet long flew past Earth this morning at a distance of about 44,000 miles. That's a close shave in cosmic terms, but astronomers had been monitoring the rock for several months and were confident there was no chance of collision.

Scientists estimate this asteroid, designated 2009 DD46, is about the same size as the body that exploded over Tunguska, Siberia, in 1908. If such a body exploded over a major city, for example, the city would be obliterated.

Asteroid 2009 DD46 is the latest reminder that Earth will be hit by a large body again unless we develop the capability to deflect such bodies into safe orbits.