David A. J. Seargent holds an MA and Ph.D., both in Philosophy from the University of Newcastle NSW, where he formerly worked as a tutor in Philosophy for the Department of Community of Programs/Worker’s Educational Association external education program. As an amateur astronomer, he is known for his observations of comets, one of which he discovered in 1978. He is the author of six astronomy books: “Comets – Vagabonds in Space” (Doubleday, 1982), “The Greatest Comets in History” (Springer, 2008), “Weird Astronomy” (Springer, 2010), “Weird Weather” (Springer, 2012), "Weird Worlds" (Springer, 2013), and most recently "Weird Universe" (Springer, 2015). He is the author of a regular column in “Australian Sky and Telescope” magazine.