This engaging picture book biography shows how pioneering astronomer Vera Rubin, who discovered evidence for the existence of dark matter, the most mysterious substance in the universe, changed people's understanding of both the universe and what a woman can do.

"Vera Rubin was one of the astronomers who discovered and named dark matter, the thing that keeps the universe hanging together. Throughout her career she was never taken seriously as a scientist because she was one of the only female astronomers at that time, but she didn't let that stop her. She made groundbreaking and incredibly significant discoveries that scientists have only recently been able to really appreciate-and she changed the way that...

"As a child, Maria Mitchell longed to see beyond her little island of Nantucket. With help from her father, she discovered that, if you knew how to read them, the stars could tell you where you were -- and where you needed to go. Maria spent hours on the roof of her house scanning the sky -- finding constellations, nebulae, meteors, double stars. When the King of Denmark offered a prize to the first person to find a new comet, she did just that. In...