We know Jupiter was hit by the Shoemaker-Levy comet, then a second major collision (making a earth-sized hole in its upper atmosphere) about 12 years later. Saturn's rings got plugged by a large “something” earlier this year - large enough to create a long dust plume of material pulled from the ring. So figure 1 planet-busting collision in Saturn or Jupiter every five years. We know that many have hit!
Earth seems largely missed though - the AZ Meteor Crater was about 50,000 years ago - and I know of none more recently than that.
So - how large a hole (megaton bomb range ??) do these “car-sized rocks” make?
Why would we not see 100 to 300 “recent” craters from these speckling the surface - if they really were as frequent as this article implies?
Why would we not see 100 to 300 “recent” craters from these speckling the surface - if they really were as frequent as this article implies?
Speculation: the population of asteroids per unit volume is sparser inside the orbit of Mars?? (Plus, also remember that the gravity well of the big gas giants extends a lot further than the puny rocky inner planets.)