50-meter asteroid will come within 17,000 miles of Earth on 2/15/2013

"Since regular sky surveys began in the 1990s," says Don Yeomans of NASA's Near Earth Object Program says, "we've never seen an object this big get so close to Earth." That's about 5% of the average distance between the Earth and the Moon. (See also: The Last Policeman: solving a murder before an asteroid wipes out life on Earth.)