The giant Chicxulub crater in Mexico provides indisputable evidence that a huge asteroid, about six miles across, struck Earth around the time many of the last dinosaur species were becoming extinct  But this catastrophe was probably not responsible for most of these extinctions  Any major asteroid strike kills many organisms in or near the region of the impact, but there is little evidence that such a strike could have a worldwide effect
Indeed, some craters even larger than the Chicxulub crater were made during times in Earth' s history when there were no known extinctions
The size of a crater caused by an asteroid striking Earth generally depends on both the size of that asteroid and the force of its impact.