Martin F. McCarthy, S.J., astronomer at the Vatican Observatory from 1958 until his retirement in 1999, died peacefully on 5 February at the age of 87 years at the Jesuit Campion Health Center in Weston, Massachusetts where he had resided since his retirement. McCarthy received his doctorate in astronomy from Georgetown University, Washington, DC in 1951. Upon completion of his seminary studies in theology, he carried out post-doctoral research at Warner and Swasey Observatory, Lick Observatory, the Dominion Astrophysical Observatory and Yerkes Observatory until he began his career at the Vatican Observatory where he served as a key figure in the Observatory’s transition to the world of modern research. He also brought the Observatory onto the international stage through his collaborations in research at, among other institutes, Palomar Observatory, Lowell Observatory, Las Campanas Observatories, the Cerro Tololo Interamerican Observatory and the Carnegie Institute of Washington. He served on the Executive Council of the Italian Astronomical Society (1969-1971), was chair of the National Committee of the Vatican to the International Astronomical Union (IAU) from 1979 until his retirement and was President of IAU Commission 25 (1976-1979). During his career he published more than 120 research papers. Among his many contributions to the growth of the Vatican Observatory, he was responsible in 1986 for the beginning of the series of the Vatican Observatory Summer Schools in Astrophysics, an initiative which has become world renowned.