Alan R. Hildebrand
Alan Russell Hildebrand (born 1955) is a planetary scientist and Associate Professor in the Department of Geoscience at the University of Calgary. He has specialized in the study of asteroid impact cratering, fireballs and meteorite recovery. His work has shed light on the extinction event caused by the Chicxulub asteroid at the end of the Cretaceous period. Hildebrand is one of the leaders of the Prairie Meteorite Network search project. Education and career. Hildebrand got a B.S. in Geoscience at The University of New Brunswick in 1977. He got a Ph.D. in Planetary Sciences at The University  of Arizona under William Boynton in 1992 with the dissertation "Geochemistry and stratigraphy of the Cretaceous/Tertiary boundary impact ejecta". In 1978 the Chicxulub Crater in the Yucatan Peninsula of Mexico was discovered by Glen Penfield, but its significance was not recognized at the time. In 1990, as part of his doctoral program, Hildebrand, working with the father-and-son team of Luis and Walter Alvarez, published controversial articles suggesting that a large impact from an asteroid caused the mass extinction at the end of the Cretaceous period. The impact site was eventually determined to be at Chicxulub and the  extinction it caused became known as the K-T event. Hildebrand is part of the Geological Survey of Canada, focusing mainly on the K-T event. External links.