Named in honor of Robert S. Harrington {1942–1993}, astronomer at the U.S. Naval Observatory in Washington and director of the program to determine parallaxes and proper motions of faint nearby stars. A leading investigator on the orbital characteristics of Pluto’s satellite and the mass of Pluto, he has made observational and theoretical studies of the motions of the planets and satellites and likely evolutions leading to the current distribution of the planets. He has also investigated the possible existence of another principal planet in the solar system. (M 11160) _ _.