S2 discovered in comet



The recent approach of comet IRAS-Araki-Alcock (1983d) to within 5 million km of earth on May 11, 1983, was an unprecedented opportunity to study processes occurring within the coma close to the nucleus of a comet (Eos, June 28, 1983, p. 429). It was also a formidable observational challenge since, at closest approach, the angular motion of the comet was 40° per day. The International Ultraviolet Explorer (IUE) Observatory (Eos, June 3, 1980, p. 481) operated from the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, was able to meet the challenge and provided Paul D. Feldman of the Johns Hopkins University and Michael F. A'Hearn of the University of Maryland with an unexpected discovery—the presence of S2 in the comet.