Groundbreaking astronomer Vera Rubin, who helped discover evidence of the existence of dark matter, has passed away at 88, her son announced on Monday.
The daughter of Jewish immigrants to the United States, Rubin said in 1996 that she considered herself a religious Jew, the Times of Israel reports.
Rubin studied astronomy as an undergraduate at Vassar, but could not enroll in her desired graduate program at Princeton University because women were not allowed into the program, according to Scientific American. Instead, Rubin earned a master's degree in physics at Cornell and completed a Ph.D. at Georgetown University, where she eventually joined the faculty.
In 1965, she moved to the Department of Terrestrial Magnetism at the Carnegie Institution in Washington, where she stayed for the rest of her career.
A few years later, she and collaborator Kent Ford made a breakthrough when studying the motion of stars in the Andromeda Galaxy, leading to then-controversial, and later widely accepted, theorizing about the existence of the universe's mysterious dark matter.
Among Rubin's many honors were becoming the second female astronomer elected to the National Academy of Sciences and receiving the National Medal of Science from President Bill Clinton in 1993.
Dark matter, a force that is not fully understood, makes up 27 percent of the universe, compared to the as five percent of the universe that is normal observable matter.