from cnn.com: Only in space would 2 million miles be considered a close call. An asteroid with an estimated diameter of three football fields zoomed by Earth late Monday, missing our home by about that distance. It traveled at some 27,000 miles per hour. The asteroid came just about a year after a relatively small asteroid blew up over Russia. The roughly 60-foot space rock plunged into Earth's atmosphere and exploded over the city of Chelyabinsk with the force of about 30 early nuclear bombs.