Posted: Sat, Dec 31, 2016, 10:47 AM ET (1547 GMT)
Vera Rubin, a pioneering astronomer who discovered evidence for the existence of dark matter, died Dec. 25. Rubin, 88, spent much of her career at the Carnegie Institution in Washington, studying the rotation of galaxies. She concluded that the rotational speeds of those galaxies could only be explained if the galaxies were embedded in a much larger halo of unseen, or dark, matter. Rubin won a National Medal of Science in 1993 and was the second female astronomer elected to the National Academy of Sciences.

Related Links:

•  AP article
•  BBC article
•  Reuters
•  NPR article
•  Carnegie Science press release