Physics & Astronomy and Geology Seminar: The Flyby Model for Chondrule and Chondrite Formation

William Herbst, John Monroe Van Vleck Professor of Astronomy at Wesleyan University, will speak. Chondrules are mm-scale igneous spherules that are a major component of the most common kind of meteorite in our collections — the chondrites. Their origin has puzzled cosmochemists and astrophysicists for decades and is still regarded as the outstanding unsolved mystery of the field by many. I will describe a new theory of their origin which accounts for distinctive properties of chondrules, such as their thermal history and age distribution, while providing potential explanations for puzzling aspects of chondrites, including complementarity, chondrule size distribution and cluster chondrites. The flyby model also makes testable predictions about the structure of primitive asteroids and meteoroids and about the history of planet formation in the inner solar system.