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
Iridium Alvarez proposed in 1980 an extraterrestrial origin for this iridium, attributing it to an asteroid or comet impact. Their theory, known as the Alvarez hypothesis, is now widely accepted to explain the extinction of the non-avian dinosaurs. A large buried impact crater structure with an estimated age of about 66 million years was later identified under what is now the Yucatán Peninsula (the Chicxulub crater). Dewey M. McLean and others argue that the iridium may have been of volcanic origin instead, because Earth's core is rich in iridium, and active volcanoes such as Piton de la Fournaise, in the island