Dr. Levison's principal research interests lie in the area of the dynamics of astronomical objects. In particular, he focuses on the formation and long-term behavior of the solar system bodies. His work includes studies of the formation of both giant and terrestrial planets, the long-term dynamical behavior of comets, the dynamics of objects in the Kuiper belt, the origin and stability of Trojan asteroids, and the formation of satellites. In 1997, he, with Martin Duncan, predicted the existence of the Scattered Comet Disk. He is best known for his work on the early dynamical evolution of the outer Solar System.