Dr. Sheehan is a practicing psychiatrist, amateur astronomer, experienced Mars observer, a contributing editor to Sky & Telescope, historian of astronomy, and first-rate author. His books include, "Planets & Perception" (1988), "Worlds in the Sky" (1992), the first biography of one of the greatest observers of all time, "The Immortal Fire Within: The Life and Work of Edward Emerson Barnard" (1995), "The Planet Mars" (1996), "In Search of Planet Vulcan" (with Richard Baum, 1997), "Epic Moon" (with T.A. Dobbins, 2001), "Mars" (with S.J.

Born in Iowa, Dr. Sandage was Staff Astronomer Emeritus with the Observatories of the Carnegie Institution of Washington, and a senior research scientist at the Space Telescope Science Institute. His research involved stellar evolution, galaxies, the extragalactic distance scale, the value of the Hubble Constant, the deceleration parameter, and the age of the Universe. Early in his career, he joined the Hale Observatories, initially as an assistant to Edwin Hubble.

Leif Robinson was Editor Emeritus of Sky & Telescope. He joined the magazine in 1962 and served as its Editor from 1980 until his retirement in 2000. Not only has Robinson made a major contribution to the dissemination of astronomical knowledge through nearly four decades at Sky & Telescope, but he remains active in matters astronomical and continues to write for that magazine.

Dr. Phillip James ("Jim") Edwin Peebles is a native of Winnipeg and a graduate of the University of Manitoba (B.Sc. in physics, 1958). He received his Ph.D. from Princeton University in 1962, and currently is a professor of physics at Princeton. In the mid-1960s, he and his colleagues predicted that thermal electromagnetic radiation from the very early Universe should be detectable by radio telescopes, that this radiation should be isotropic, and that it should have the spectrum of a black body only a few degrees above absolute zero.

Dr. Pasachoff was the Field Memorial Professor of Astronomy and Director of Hopkins Observatory at Williams College in Williamstown, Massachusetts, U.S.A. His research involves planetary atmospheres, the interstellar medium, and solar physics. He observed many total solar eclipses while pursuing studies of the solar chromosphere and corona. Dr. Pasachoff has an international reputation for his contributions to education in astronomy.

Born in England in 1923, Patrick Alfred Caldwell-Moore has been England's pre-eminent popularizer of astronomy for the past half century, and he continues to be an ambassador for astronomy. He was elected a member of the British Astronomical Association while he was still a school-boy, and became its president 50 years later. During World War II, he served with the Royal Air Force. He established his private observatory at Selsey, in Sussex, U.K., where he specializes in observations of the Moon and planets.

Jean Meeus is a Belgian meteorologist and astronomer. Born in 1928, Jean Meeus studied mathematics at the University of Louvain (Leuven) in Belgium, receiving the Degree of Licentiate in 1953. From then until his retirement in 1993, he was a meteorologist at Brussels Airport. His special interest is in spherical and mathematical astronomy. He is the co-author of "Canon of Solar Eclipses" (1966 and 1983), and "Canon of Lunar Eclipses" (1979).

Dr. Hawking was a British theoretical physicist and cosmologist, and Lucasian Professor of Mathematics at Cambridge University. He was a leader in the study of some of the most fundamental problems in physics and astronomy, notably the nature of gravity, its relation to the other forces and to quantum and particle physics, and its application to cosmology. One of his discoveries is that black holes should radiate as if they were hot bodies. Among Dr. Hawking's many honours was his election as a Fellow of the Royal Society in 1974.

Reverend Robert Evans, an Australian amateur astronomer, holds the world record for visual discoveries of supernovae: 42, more than the combined total of all other visual observers combined! Most of these were found using Newtonian telescopes of 10-, 12-, and 16-inch aperture from his backyard.

Dr. Audouin Dollfus was a French astrophysicist who for many years was Head of the Laboratory for Physics of the Solar System at Meudon Observatory in Paris. He is a leading planetary observer. In the 1950s, Dollfus made several balloon flights for high-altitude observations of the Sun and planets, including the first stratospheric ascension in France. He was one of the first to notice brightness ripples in the rings of Saturn. In 1966, when the rings of Saturn were edge-on, he discovered the 10th satellite of Saturn, Janus, orbiting just outside the bright ring system.