Vera Rubin

Vera Rubin was an American astronomer whose observations provided some of the strongest early evidence for the existence of dark matter in galaxies. Working with instrument-maker Kent Ford beginning in the late 1960s, Rubin measured the rotation speeds of stars and gas at different distances from the center of spiral galaxies and found that stars far from a galaxy's visible center were orbiting just as fast as those closer in, contrary to what the visible, luminous matter alone would predict under standard gravitational theory. This flat rotation curve pattern, confirmed across dozens of galaxies Rubin studied, strongly suggested that each galaxy contains a large amount of unseen mass, now generally called dark matter, extending well beyond its visible edges. Rubin pursued this research over a long career at the Carnegie Institution's Department of Terrestrial Magnetism despite facing significant institutional barriers as one of relatively few women in astronomy at the time, including having been formally excluded from observing time at some major U.S. observatories earlier in her career. Rubin's rotation curve findings remain one of the central pieces of observational evidence motivating the continued scientific search for dark matter, and the Vera C. Rubin Observatory in Chile was named in her honor.