Career
He is a prolific discoverer of asteroids. His special interest is the orbit/course of the asteroids. He has discovered numerous asteroids such as 8661 Ratzinger, 10114 Greifswald and 11508 Stolte.
He is the author of Dictionary of Minor Planet Names (see below) a reference book containing information about the discovery and naming of 12,804 asteroids (March 2006).
One asteroid 2234 Schmadel, discovered in 1977, was named in his honor.