From a young age, Marie Tharp wanted to be a scientist. In the mid-twentieth century, women were not welcome in the sciences, but Marie got a job in a laboratory at Cambridge University, New York. But then she faced another barrier: women were not allowed on the research ships (they were considered bad luck on boats). So instead, Marie mapped point after point and slowly revealed a deep rift valley in the ocean floor. She mapped the single largest geographic feature on the planet, all from her small, cramped office.