He is the recipient of the Warner, Heinemann, and Brouwer awards of the American Astronomical Society, the Beals Award of the Canadian Astronomical Society, and the Steacie Prize (NSERC) and honourary Doctor of Science degrees from McMaster and St. Mary’s University. His research is focused on the dynamics and evolution of a wide variety of astrophysical systems, including comets, galaxies, massive black holes, planetary rings, and planetary systems.