A Close Call with a Near-Earth Asteroid

On February 15th, a near-Earth asteroid passed within 17,200 miles of our planet's surface (27,600km). The asteroid, formally designated as 2012 DA14, is an estimated 150 feet across (or about 45 meters wide), which is about half the size of a football field. It is composed of approximately 140,000- tons of stone (instead of metal or ice).

Learn more at: http://www.fromquarkstoquasars.com/a-close-call-with-a-near-earth-asteroid/