There aren't many asteroids in orbit around Earth as Savage states - well, actually, none. Savage is using meteors, not asteroids, but he says the asteroid has an iron core. Later he correctly says "meteor" ("The first time a meteor gave me power..."). Technically asteroids are rocks in space, meteoroids are rocks passing through the atmosphere, meteors are the flash caused by meteoroids, and meteorites are meteoroids that reach the ground. In any case, there is nowhere near as many asteroids near Earth as this episode depicts. If there were, gravity would cause them to rain down and destroy the cities of Earth on a daily basis.