William Sheehan is the author or coauthor of a number of widely acclaimed books on astronomy, including Mars: The Lure of the Red Planet (with Stephen James O'Meara), The Immortal Fire Within (a biography of Edward Emerson Barnard), The Planet Mars, and Epic Moon (with Thomas Dobbins). The author of over a hundred popular articles on astronomy, he is a contributing editor to Sky & Telescope, a frequent contributor to Mercury, and a 2001 fellow of the John Simon Guggenheim Memorial Foundation for the "structure and evolution of the Milky Way Galaxy."
John Westfall is a professor of geography at San Francisco State University, the recipient of the Walter Haas Observing Award from the Association of Lunar and Planetary Observers, and the author of the Atlas of the Lunar Terminator.