163693 Atira, provisional designation 2003 CP20, is an eccentric, stony asteroid, dwelling in the interior of Earth's orbit. It is classified as a near-Earth object. Atira is a binary asteroid, a system of two asteroids orbiting their common barycenter. The primary component with a diameter of approximately 4.8 kilometers is orbited by a smaller object that measures about 1 kilometer. Atira was discovered on 11 February 2003, by the Lincoln Near-Earth Asteroid Research (LINEAR) team at Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States.