DISTINGUISHED PLANETARY SCIENTIST TO TALK ABOUT METEORITE IMPACT CRATERS ON THE MOON AND EARTH

FAYETTEVILLE, Ark. - Dr. Christian Koeberl, a cosmochemist at the Institute of Geochemistry of the University of Vienna in Austria, will be visiting the University of Arkansas next week to present the fall 2001 Barringer lecture.

He will give a talk about meteorite impact craters entitled "Impacts, Volcanoes, Glaciers, Coral Reefs, and Lunar Cows: A History of Theories of the Origin of Craters on the Moon and Earth." It is free to the public and will take place in Giffels Auditorium in Old Main at 7 p.m., Monday, Nov. 12.

"Most of us think of the major impact of an object from outer space as a harbinger of death and destruction, and usually it is," Koeberl said. "It was the impact of an asteroid into the Earth, just off the coast of Mexico 60 million years ago that destroyed the dinosaurs, and an impact of an extraterrestrial object into the desert of Arizona 50,000 years ago that created a hole one mile wide."

Impact cratering is now recognized by many to be a very important, if not the most important, surface-modifying process in the planetary system, Koeberl added.

"It is now fairly widely accepted that our moon, Mercury, Venus, Mars, asteroids, and the moons of the outer gas planets are all peppered with meteorite impact craters," Koeberl said. "However, this knowledge is fairly recent. Well into the 20th century, it was well known that all the lunar craters were of volcanic origin and of course the presence of craters on any of the outer bodies was not known until spacecraft visitation was possible."

The origin of lunar craters had been discussed for centuries, with a variety of exotic explanations that included tidal forces, circular glaciers, coral atolls and even lunar meadows with grazing cows. The meteorite impact hypothesis was considered a few times, but only gained momentum early in the 20th century. Koeberl said there are very important lessons that can be learned from the history of the study of impact craters on the Earth.

The Barringer Lectures are sponsored by the Barringer Crater Company (owners of the Arizona meteor crater) and are hosted by the Arkansas-Oklahoma Center for Space & Planetary Sciences, the University's departments of Chemistry and Biochemistry, Geology and Physics, and the University Museum.

For further information about the Barringer lecture series please contact Derek Sears at the Arkansas-Oklahoma Center for Space and Planetary Sciences, UA department of Chemistry and Biochemistry at 479-575-5204 or by e-mail at csaps@uark.edu or visit http://www.uark.edu/csaps.