Michael K. Shepard is Professor of Geosciences at Bloomsburg University of Pennsylvania, specialising in remote sensing, planetary photometry and asteroid studies. He is the author of the popular science book Asteroids: Relics of Ancient Time (Cambridge, 2015), articles for popular science magazines like Sky and Telescope, and a guest science column for the regional Press Enterprise newspaper. He has previously worked at the National Air and Space Museum, Washington DC and the Jet Propulsion Laboratory, California Institute of Technology.