John Spencer is an astronomer at Lowell Observatory in Flagstaff, Arizona, where he primarily works on observational studies of the Galilean satellites. He is leader of the International Jupiter Watch Satellite Discipline, and was heavily involved in the comet crash campaign, coordinating filter purchases, disseminating information by e-mail, producing a computer animation of the impacts, writing an article for the Planetary Society magazine, and observing the impacts with an infrared camera in Chile.
spencer@lowell.edu