Marsden has computed an incredible number of comet and asteroid orbits, allowing other scientists to pursue research based on his reliable orbits. Marsden successfully predicted the return of Comet Swift-Tuttle, and is the celestial mechanician who discovered that Comet Shoemaker-Levy 9 would impact Jupiter in mid-1994. He helped pioneer the investigation of the effects of non-gravitational forces on comet orbits. In addition to his personal research, Marsden's chief duty has been to produce enormous quantities of information and to transmit it to astronomers world-wide through the IAU and Minor Planet Circulars, a task in which he has excelled to the benefit of us all.

The selection of Dr. Marsden was announced at the recent annual meeting of the DDA, and he will give the Brouwer Award Lecture at the next meeting of the DDA in Washington, DC.