" . . . bangs have replaced whimpers and the geological record has become much more exciting than it was thought to be. " Derek Ager (1993) The New Catastro- phism. Cambridge University Press, Cambridge, p xix Scientific and public interest in asteroids, comets, and meteorite impacts has never been more intense than right now. Much of this interest stems from the fervent debates surrounding the causes of the Cretaceous-Tertiary mass extinctions and their possible relationships to a giant bolide impact in Mexico's Yucatan Penin- sula. Recent spectacular impacts on Jupiter, and several near...