Brian Geoffrey Marsden, Director Emeritus of the Minor Planet Center, which collects worldwide data on the positions of asteroids and comets, died on 18 November. He was 73.
“Brian was one of the most influential comet investigators of the twentieth century and definitely one of the most colorful,” said Charles Alcock, Director of the Harvard-Smithsonian Center for Astrophysics, in a statement.
Marsden was born 5 August, 1937, in Cambridge, England. He received an undergraduate degree in mathematics from the University of Oxford in the UK, and in 1965 earned his PhD from Yale University in Connecticut. That same year he arrived at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, where he would make his professional home for the duration of is career. In 1968 Marsden took over as Director of the Central Bureau for Astronomical Telegrams and for the next 32 years he fielded reports of newly discovered comets, asteroids and supernovae from observers around the world. By 1978 he had added the Minor Planet Center directorship to his duties and became widely known as an authority on the smaller bodies of the solar system. Among his achievements was the linking of Comet Swift-Tuttle, the source of the annual Perseid Meteor shower, to a “lost” comet seen in 1737. On this basis, he correctly predicted that Swift-Tuttle would return in 1992, eleven years later than previously thought.
As a minor planet maven, Marsden also found himself at the centre of a major uproar in 1998 when he suggested to a New York Times reporter that a newly discovered 2-km-sized asteroid could collide with Earth in 2028. The object was soon found to pose no threat and Marsden later clarified that he had said the impact would have happened “only under highly unusual circumstances”. The episode sparked a lively and ongoing debate over how astronomers should best convey news of possible impact threats to the general public.
Marsden was recognized with the Van Biesbroeck Award, by University of Arizona, for his services to astronomy, 1989 and the Brouwer Award, by American Astronomical Society, for research in dynamical astronomy in 1995.