DAVID LEVY has discovered 21 comets since 1984 - eight from his own backyard and 13 others as part of the Shoemaker-Levy team at Palomar. He also writes a column for 'Sky and Telescope', is the author of eight books, and the winner of the 1993 Amateur Achievement Award, which recognized his contribution in the field of astronomy.
DR JOHN O'BYRNE lectures in the School of Physics at Sydney University. He has a broad range of theoretical interests and is a Secretary of the Astronomical Society of Australia.
WIL TIRION drew the sky maps and constellation charts for this publication. He started making star atlases as a hobby in1977 and in 1983 he became a full-time sky cartographer.
ROBERT BURNHAM has been an amateur since the late 1950s. His main interests revolve around observing the Moon and planets by telescope but he also enjoys reading about cosmology. An active amateur geologist and birder, he is at present the Editor in Chief of 'Astronomy' magazine.