William Sheehan is an amateur astronomer, psychiatrist, and writer. He received a bachelor’s degree from the University of Minnesota, a master’s degree from the University of Chicago, and an MD degree from the University of Minnesota. He also completed residency training in psychiatry at the University of Minnesota. Sheehan’s first book, Planets and Perception: Telescopic Views and Interpretations, 1609–1909, was named a 1988 book f the year by the Astronomical Society of the Pacific. Dr. Sheehan has also published numerous articles in astronomy and psychiatry. His interest in the Moon and planets goes back to the early days of the spacecraft era, and he regularly observes with a six-inch refractor and a twelve-and-a-half-inch reflector from his home in St. Paul, Minnesota.