Michael Aschbacher, the Shaler Arthur Hanisch Professor of Mathematics, has been awarded the 2012 Leroy P. Steele Prize for Mathematical Exposition by the American Mathematical Society (AMS). Aschbacher, along with coauthors Richard Lyons of Rutgers University, Steve Smith of the University of Illinois at Chicago, and Ronald Solomon of Ohio State University, were recognized for a paper on the classification of certain types of groups, which are fundamental mathematical objects.