Vera Rubin was an American astronomer born on July 23, 1928, in Philadelphia, Pennsylvania. She is best known for her pioneering work on the rotation curves of galaxies, which provided strong evidence for the existence of dark matter. Rubin's research demonstrated that galaxies rotate at such speeds that they should fly apart, yet they remain intact, suggesting the presence of unseen mass. Throughout her career, Rubin faced significant challenges as a woman in a male-dominated field. She earned her Ph.D. from Georgetown University in 1954 and later worked at the Carnegie Institution of Washington. Rubin's contributions to astronomy have had a lasting impact, influencing our understanding of the universe.