Asteroid Comes Close to Earth

The asteroid 2012 DA14 may not have a scary name but, if it were to strike planet Earth, the destruction could be colossal. An asteroid that struck the Earth is blamed for ending the age of the Dinosaurs. Others have caused enormous craters on several continents. About one million such rocks are orbiting in the solar system, but such a collision is very rare. Tomorrow, 2012 DA14 will come closer to Earth than stationary GPS satellites. Phil Plait, who writes the Bad Astronomer blog for Slate.com, has more on this reassuring news and on what astronomers hope to learn.