Astronomers say newly found large asteroid poses no threat to Earth MOSCOW, Oct. 11 (UPI) -- Russian astronomers say they detected a near-Earth asteroid about a fifth the size of the space rock thought to have killed the dinosaurs 65 million years ago. The half-mile-wide asteroid, dubbed 2013 TB80, was first spotted Wednesday by a Russian-operated observatory in New Mexico and later confirmed by U.S. and Japanese astronomers, the International Astronomical Union said in an online statement. The asteroid does not pose a threat of colliding with Earth, the head of the remotely run observatory that made the discovery said. "It's a big asteroid, but it poses no danger for us," Leonid Elenin, who lives near Moscow, told RIA Novosti Friday. Near-Earth objects, or NEOs, are defined as those that come as close to the Sun as the Earth does, which means they have a chance of colliding with our planet. NASA estimates 93 percent of near-Earth asteroids above one kilometer in diameter have been identified, and none of them is expected to collide with the Earth in the foreseeable future.