Margaret Turnbull is a distinguished American astronomer renowned for her extensive work on identifying potentially habitable star systems. She developed the Catalog of Nearby Habitable Systems (HabCat), a crucial database listing stellar systems that might support complex life. Her research has been instrumental in guiding the search for extraterrestrial intelligence (SETI) by shortlisting the most promising target stars. Turnbull continues to be a significant voice in the fields of astrobiology and extrasolar planet detection, contributing to our understanding of life's potential in the universe.