The many challenges of exploring hidden realms

Imagine a young woman who sought to explore the oceans’ depths but was barred from going to sea. From her desk in New York City in the 1950s, she used bits of data gathered by the ships she couldn’t sail on to create maps that revolutionized our understanding of the seafloor and helped revise Earth’s history. Her name was Marie Tharp.

Then imagine other scientists, many decades later. They traveled to Antarctica for mapping projects of their own. Like Tharp, the researchers faced obstacles: The river they sought lies under hundreds of meters of solid ice. So the team patched together clues, including a wrinkle on the surface of a glacier, which led to the discovery of a spectacular river-carved cavern beneath the ice that’s almost as tall as the Empire State Building.