Dave Schleicher

PhD, 1983, University of Maryland

Dr. Dave Schleicher’s major research interests include the physical properties, chemical composition, and behavior of comets. He uses a variety of observational tools plus theoretical modeling in his studies. In 1986, he discovered with Dr. Robert Millis the periodic variability of Comet Halley — a discovery that profoundly affected the interpretation of all observations of the comet including those from the Giotto and Vega craft.

In recent decades, Dr. Schleicher’s team routinely obtain CCD imaging of comets to detect gas and dust jets emitted from each comet’s nucleus. The shape and motion of these jets during a night and over the course of weeks and months are used to determine not only how fast these bodies rotate but also the orientation of the axis of rotation and the location and size of each active source region on the surface. Such findings, in turn, help explain the strong seasonal effects sometimes measured: the amount of gas released often depends more on the orientation of the nucleus rather than just the distance from the Sun.

Dr. Schleicher is also an accomplished photographer.