Well all i can say is thank jupiter . Because it has such a strong gravitanal force that it captures most of the larger bodies traveling through our solar system we seem to be spared many many large size impacts because of this just another cosmic chance that added up to life on earth. It wasnt that long ago jupiter had a massive strike something the size of our moon it would have completly destroyed life on earth but not that great affect on the gas gaint .but we could see it .