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win had suggested such a possibility in anarticle in popular astronomy magazine。 （he published the article there because no academicpublisher was prepared to run it。） and at least two well…known scientists； the astronomerernst ？pik and the chemist and nobel laureate harold urey； had also voiced support for thenotion at various times。 even among paleontologists it was not unknown。 in 1956 a professorat oregon state university； m。 w。 de laubenfels； writing in the journal of paleontology； hadactually anticipated the alvarez theory by suggesting that the dinosaurs may have been dealt adeath blow by an impact from space； and in 1970 the president of the americanpaleontological society； dewey j。 mclaren； proposed at the group’s annual conference thepossibility that an extraterrestrial impact may have been the cause of an earlier event knownas the frasnian extinction。
as if to underline just how un…novel the idea had bee by this time； in 1979 ahollywood studio actually produced a movie called meteor （“it’s five miles wide 。 。 。 it’sing at 30；000 m。p。h。—and there’s no place to hide！”） starring henry fonda； nataliewood； karl malden； and a very large rock。
so when； in the first week of 1980； at a meeting of the american association for theadvancement of science； the alvarezes announced their belief that the dinosaur extinctionhad not taken place over millions of years as part of some slow inexorable process； butsuddenly in a single explosive event； it shouldn’t have e as a shock。
but it did。 it was received everywhere； but particularly in the paleontological munity；as an outrageous heresy。
“well； you have to remember；” asaro recalls； “that we were amateurs in this field。 walterwas a geologist specializing in paleomagnetism； luis was a physicist and i was a nuclearchemist。 and now here we were telling paleontologists that we had solved a problem that hadeluded them for over a century。 it’s not terribly surprising that they didn’t embrace itimmediately。” as luis alvarez joked： “we were caught practicing geology without alicense。”
but there was also something much deeper and more fundamentally abhorrent in the impacttheory。 the belief that terrestrial processes were gradual had been elemental in natural historysince the time of lyell。 by the 1980s； catastrophism had been out of fashion for so long that ithad bee literally unthinkable。 for most geologists the idea of a devastating impact was； aseugene shoemaker noted； “against their scientific religion。”
nor did it help that luis alvarez was openly contemptuous of paleontologists and theircontributions to scientific knowledge。 “they’re really not very good scientists。 they’re morelike stamp collectors；” he wrote in the new york times in an article that stings yet。
opponents of the alvarez theory produced any number of alternative explanations for theiridium deposits—for instance； that they were generated by prolonged volcanic eruptions inindia called the deccan traps—and above all insisted that there was no proof that thedinosaurs disappeared abruptly from the fossil record at the iridium boundary。 one of the most vigorous opponents was charles officer of dartmouth college。 he insisted that theiridium had been deposited by volcanic action even while conceding in a newspaper interviewthat he had no actual evidence of it。 as late as 1988 more than half of all americanpaleontologists contacted in a survey continued to believe that the extinction of the dinosaurswas in no way related to an asteroid or etary impact。
the one thing that would most obviously support the alvarezes’ theory was the one thingthey didn’t have—an impact site。 enter eugene shoemaker。 shoemaker had an iowaconnection—his daughter…in…law taught at the university of iowa—and he was familiar withthe manson crater from his own studies。 thanks to him； all eyes now turned to iowa。
geology is a profession that varies from place to place。 in iowa； a state that is flat andstratigraphically uneventful； it tends to be paratively serene。 there are no alpine peaks orgrinding glaciers； no great deposits of oil or precious metals； not a hint of a pyroclastic flow。
if you are a geologist employed by the state of iowa； a big part of the work you do is toevaluate manure management plans； which all the state’s “animal confinement operators”—hog farmers to the rest of us—are required to file periodically。 there are fifteen million hogsin iowa； so a lot of manure to manage。 i’m not mocking this at all—it’s vital and enlightenedwork； it keeps iowa’s water clean—but with the best will in the world it’s not exactly dodginglava bombs on mount pinatubo or scrabbling over crevasses on the greenland ice sheet insearch of ancient life…bearing quartzes。 so we may well imagine the flutter of excitement thatswept through the iowa department of natural resources when in the mid…1980s the world’sgeological attention focused on manson and its crater。
trowbridge hall in iowa city is a turn…of…the…century pile of red brick that houses theuniversity of iowa’s earth sciences department and—way up in a kind of garret—thegeologists of the iowa department of natural resources。 no one now can remember quitewhen； still less why； the state geologists were placed in an academic facility； but you get theimpression that the space was conceded grudgingly； for the offices are cramped and low…ceilinged and not very accessible。 when being shown the way； you half expect to be taken outonto a roof ledge and helped in through a window。
ray anderson and brian witzke spend their working lives up here amid disordered heapsof papers； journals； furled charts； and hefty specimen stones。 （geologists are never at a lossfor paperweights。） it’s the kind of space where if you want to find anything—an extra chair； acoffee cup； a ringing telephone—you have to move stacks of documents around。
“suddenly we were at the center of things；” anderson told me； gleaming at the memory ofit； when i met him and witzke in their offices on a dismal； rainy morning in june。 “it was awonderful time。”
i asked them about gene shoemaker； a man who seems to have been universally revered。
“he was just a great guy；” witzke replied without hesitation。 “if it hadn’t been for him； thewhole thing would never have gotten off the ground。 even with his support； it took two yearsto get it up and running。 drilling’s an expensive business—about thirty…five dollars a footback then； more now； and we needed to go down three thousand feet。”
“sometimes more than that；” anderson added。
“sometimes more than that；” witzke agreed。 “and at several locations。 so you’re talking alot of money。 certainly more than our budget would allow。”
so a collaboration was formed between the iowa geological survey and the u。s。
geological survey。
“at least we thought it was a collaboration；” said anderson； producing a small painedsmile。
“it was a real learning curve for us；” witzke went on。 “there was actually quite a lot of badscience going on throughout the period—people rushing in with results that didn’t alwaysstand up to scrutiny。” one of those moments came at the annual meeting of the americangeophysical unio