Stardate 20011115.1113 (On Screen via long range sensors): The Alvarez theory hit the world of paleontology, geology and biology like a stone from the sky. (Sorry.) It posited that the reason for the mass die-off at the end of the Cretaceous, which just incidentally included the exterminaion of the dinosaurs, happened because a large body from space struck the Earth and caused a massive ecological catastrophe. Named after the father-and-son team of Luis and Walter Alvarez, who lead the group that developed the idea, it was initially greeted with shocked suprise and disbelief in many quarters -- but with eagerness in many others. And over the years the evidence in favor of it piled up until the smoking gun was finally found: the crater itself. It is called Chicxulub (Sheek-su-lube) and it is located in the Caribbean just off the Yucatan peninsula. While much research continues, it has triumphed and is now generally accepted in the scientific community as the explanation for that mass extinction event. And in the aftermath of that discovery, it is now suspected that all the other major extinction events, especially the Permian catastrophe, were also caused by impacts. The Permian event, which is the largest mass extinction in the history of the earth (dwarfing the Cretaceous event) has now been tentatively identified as having been caused by an impact in China.
But these refer to things that happened long ago, so it's stunning to learn that perhaps meteor strikes might have more immediate effect on the course of history. There was a major impact in the 20th century, for instance, but it happened at Tunguska in Siberia, possibly the least inhabited land target on earth one could imagine. (Lucky for us, too; if it had hit Paris or some other large city it would have killed nearly everyone living there.) So the Tunguska event didn't have any effect on history. Now it appears that there was a strike in southern Iraq within recorded history which may well have altered the course of Western Civilization. It is humbling to think that the juggernaut of human history is susceptible to the effects of nature in such a dramatic fashion. Certainly weather can do it, but we live with weather every day; but rocks from the sky? As little as 200 years ago the entire concept that rocks could fall from the sky was dismissed by the scientists of the time as superstition. (discussion in progress)
