CompuServe Thread

Rob, Thanks for your thoughtful reply. The fascinating thing is that meteorites are everywhere! To paraphrase Robert Dodd in his popular book, THUNDERSTONES AND SHOOTING STARS (1986, Harvard University Press), trillions of potentially recoverable meteorites have fallen since 200 years ago when these exquisite visitors were finally understood to be true E.T.'s. The problem is that meteorite recovery is a very chancy business. Meteorites fall at about the same rate over most of the Earth, with a slight decrease in the polar realms. Most meteorites up to 1977 were recovered in relation to densely populated areas. The more people that live in a particular area, the more meteorites seem to have been found. Historically, meteorites have also been sought by the scientifically incentivized French, English, and Japanese. Largely due to this, these countries and their people have disproportionately discovered the most recovered meteorites. Here in the U.S.A., starting in the depression years, Harvey H. Nininger, a former College biology teacher turned obcessed amateur meteoricist (even before scientists were really ready to embrace Meteoritics as a valid science) motivated single-handedly the recovery of huge numbers of meteorite "finds" and "falls" by single-mindedly educating the farm folks out in the American Midwest and Southwest to recognize meteorites. Those states with lots of prairies, intensive wheat/corn cultivation, and arid desserts have yielded the most finds. Other areas of the world that have similar conditions, like Nullabor desert and coastal Australia, South Africa, the arid plains of India, and the high Andean desserts of Chile have also allowed the knowledgable to locate meteorites. The surprise was Antarctica, where to date, well over 8000 meteorites have been recovered. Up to 1977, on about 2500 meteorites were known. Starting in 1977, Japanese scientists discovered a concentration of different meteorites found on a glacer of "blue ice" at the foot of the "Yamato Mountains". Apparently, glaciers act like a massive conveyor belt, picking up meteorites as they fall onto the zone of snow accumulation. In rare glacial places where there are geological barriers to the free flow of glaciers, ancient dense blue ice is dredged to the surface and scoured by arctic winds and sublimed/pulverized, leaving behind the strange accumulation of meteorites. These Antarctic meteorites are rarely available to the enthusiast, and are instead largely guarded by government institutes in Japan and the United States. Meteorites of 1 g or greater size are considered "recoverable meteorites." Estimates are that about 100-1000 tons of such meteorites or larger hit the Earth daily! Someone worked it out to about 8 meteorites of 1 gram size per square mile of Earth surface. Based on meteorite "flux" analysis, a crater-forming meteoroid of 300+ tons hits the Earth 5 times each year, but thankfully mostly unobserved splashdowns in our oceans. The bus-sized 100,000 ton Canyon Diablo meteoroid ought to hit somewhere every 60 years! A 6 mile wide K-T type meteoroid ought to hit the earth about every 50 million years on average generating mile-high Tidal waves and plummeting the Earth into a post-Meteor winter 50 times worse than the post-thermonuclear winters we used to read about…the Dinos bit the dust 65 million years ago! We're a bit overdue! The dealers and retail vendors in meteorites have developed over years and decades an intricate network of personal friends and international contacts that help to free up meteorite specimens entrenched in private collections, national museums, universities, etc. If it were not for the efforts of the likes of Robert Haag, the selection and availability of meteorites would be very limited. By swapping specimens accessible to them like the Esquel pallasites with otherwise inaccessible meteorites locked in National collections, like the Ensisheim historic meteorite of 1492, specimens become available for both the collector AND the researchers. As older private collections are given up by estates, these dealers also function as clearing houses that funnel the episodic true exotics toward patiently waiting researchers and collectors. Without the commercial or retail side of meteorite collecting, much of the truely rare meteorite exotics, like the Ureilites and various Carbonaceous chondrites, would never or very rarely become accessible to University research groups, who incidentally do use the same dealers. After reading H.H. Nininger's autobiography, FIND A FALLING STAR (1972, Paul S. Eriksson, Inc., N.Y.), it's hard not to start seeing stones and boulders in a new and naively hopeful fashion. From reading the description in the Meteoritical Bulletin of how some of the newly discovered 200 g or less meteorites are found by enthusiastic folks actively looking for meteorites with metal detectors on, say, a dry lake bed, ala Utah, I'd have to say that meteorites must be all around us. The closes recorded meteorite fall to me was in Palolo Valley a mile away from my home here in Honolulu in 4/24/49! The only other one from Hawaii fell a mere three miles away, the Honolulu fall of 9/27/1825. There may well be meteorites hiding among the basalt stones that make up my retaining wall outside, though well oxidized and virtually indistinguishable by just cursory inspection by now… I'll close now. Hope the above answers your question, Rob. -Joseph