To the best of our knowledge, for any of asteroid belt, Kuiper belt and Van Oort cloud, the trick is hitting, not missing. Space is vast; matter is (relatively

To the best of our knowledge, for any of asteroid belt, Kuiper belt and Van Oort cloud, the trick is hitting, not missing. Space is vast; matter is (relatively) sparse. Moreover, matter tends to clump together, concentrating what little there is.