Vera Rubin, astronomer, dies

Pioneering astronomer Vera Rubin, whose research led to the discovery of dark matter, dies at the age of 88. In the 1960s and ’70s, Rubin found that the rate of galaxies’ rotation could not be accounted for unless galaxies contained, on average, ten times more mass than could be distributed among the visible stars in that galaxy. This research led her to propose the theory of dark matter in the 1970s, though she tried for many years to find – or at least rule out – any other possible explanations to the galaxy rotation problem.