Alan Russell Hildebrand, a Canadian geologist, contributed a lot of the field of geology. His greatest accomplishment includes the discovery of the catastrophic Chicxulub Crater in the Yucatan Peninsula of Mexico. This discovery is considered the site of the catastrophic event that resulted in the extinction of the dinosaurs. Furthermore, Hildebrand is one of the leaders for the Prairie Meteorite Search and is a member of the Meteorites and Impacts Advisory Committee.
Currently, Hildebrand is a research scientist for the Geological Survey of Canada, with his research focusing mainly on the K-T event as well as meteorite processes and impacts. He is also part of The Geology and Geophysics Department at the University of Calgary.
So, what is the K-T event? It has been theorized that the dinosaurs became extinct 65 million years ago by a disaster that has become known as the K-T event (Cretaceous-Tertiary Mass Extinction event). Presumably an asteroid hit the earth, its impact killing 70% of the species on Earth. In 1990, Alan Hildebrand discovered the Chicxulub Crater in the Yucatan Peninsula of Mexico. The crater has a diameter of 112 mi (180 km) and has been dated at about 65 million years ago. The asteroid that is responsible for creating the Chicxulub Crater is believed to have had a diameter of 6 mi (10 km).
Alan Hildebrand is currently one of the leaders for the Prairie Meteorite Search, a national project that focuses on the discovery of meteorites by prairie farmers. Researchers involved in the project travel to prairie farms to instruct locals on what meteorites look like and examine specimens found by the farmers. Additionally, Hildebrand volunteers for the Meteorites and Impacts Advisory Committee to the Canadian Space Agency. This committee is responsible for discovering meteorites around Canada and investigates possible fireballs.
Sources: "Hildebrand, Alan Russell (1955- )." World of Earth Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Vol. 1. Gale Cengage, 2003.