2011 CQ1 is a meteoroid discovered on February 4, 2011 by Richard A. Kowalski, at the Catalina Sky Survey. On the same day the meteoroid passed within 0.85 Earth radii (5,480 kilometers (3,410 mi)) of Earth's surface, and was perturbed from the Apollo class to the Aten class of near-Earth objects. With a relative velocity of only 9.7 km/s, had the asteroid passed less than 0.5 Earth radii from Earth's surface, it would have fallen as a brilliant fireball. The meteoroid is between 80 centimeters (31 in) and 2.6 meters (100 in) wide. The meteoroid was removed from the Sentry Risk Table on February 5, 2011.