Animation of Asteroids Passing Near Earth . ... Credit Copyright: MPC , Harvard-Smithsonian CfA , IAU Explanation: How often does an asteroid whiz by the Earth? ... Some asteroids appear out of nowhere as they are plotted only when they were discovered. ... Although none of the plotted objects came inside the orbit of our Moon, our Solar System is filled with objects as small as bits of sand, usually left by a comet, that appear as meteors as they streak into the Earth's atmosphere every day. ...