METEOR MENACE--This image provided by NASA/JPL-Caltech shows a simulation of asteroid 2012 DA14 approaching from the south as it passes through the Earth-moon system on Friday, Feb. 15, 2013. (AP Photo/NASA/JPL-Caltech) by Marcia DunnAP Aerospace WriterCAPE CANAVERAL, Fla. (AP) — A space rock even bigger than the meteor that exploded like an atom bomb over Russia could drop out of the sky unannounced at any time and wreak havoc on a city. And Hollywood to the contrary, there isn't much the world's scientists and generals can do about it. But some former astronauts want to give the world a fighting chance.
