sky, a meteor. >> it is about ten miles off the highway that went in to the brush area. >> reporter: the shooting star lit up 911 call centers across the southwest. >> across the sky. >> reporter: we all saw the movie "armageddon," right? >> see that? >> reporter: how worried should we be? how big does it need to be before we put bruce willis on a spaceship? >> i presume it has to be big enough to walk around on. the average meteor strike is left usually by something no bigger than a pea. >> reporter: fiery rocks a big enough concern the u.n. has started to consider a plan to create an international asteroid warning network. astronomers not too worried about the big stuff, like the meteor that killed off the dinosaurs. that one was the size of mt. everest. no, what scares them more are meteors like the one that hit russia earlier this year. that one as big as a house. it could flatten a city.