Catherine Corrigan Catherine Corrigan Catherine Margaret Corrigan (born 1972), often known as Cari Corrigan, is an American scientist best known as a curator of the meteorite collection at the Smithsonian Institution. She is a scientist in the Department of Mineral Science at the National Museum of Natural History. Corrigan obtained a Bachelor of Science in 1995 and a Master of Science in 1998, both in Geology at Michigan State University. Her master's thesis was titled "The Composition of Impact Breccias from the Chicxulub Impact Crater, Yucatan Peninsula, Yucatan, Mexico". She later earned a Ph.D in Planetary Science at Case Western Reserve University
Chicxulub crater apart. In late 2006, Ken MacLeod, a geology professor from the University of Missouri, completed an analysis of sediment below the ocean's surface, bolstering the single-impact theory. MacLeod conducted his analysis approximately from the Chicxulub crater to control for possible changes in soil composition at the impact site, while still close enough to be affected by the impact. The analysis revealed there was only one layer of impact debris in the sediment, which indicated there was only one impact. Multiple-impact proponents such as Gerta Keller regard the results as "rather hyper-inflated" and do not agree with the conclusion of MacLeod's