It has been said that the human race knows more about certain distant galaxies than it does about the ground that lies beneath its very feet. In fact, while it took the famous Voyager 1 satellite 26 years to exit our Solar System (relaying measurements to Earth from 16.5 billion km away), it took about the same amount of time for humanity to penetrate a mere 12 km into the Earth’s surface. The Russians dug a nine-inch diameter hole 7.5 miles under the ground just to see what was there-until the Earth’s crust started melting their equipment. You can’t dig a hole to China, but Russia and the U.S. came close. Starting in the 1970s, the superpowers started to drill a hole deep into the Earth’s crust. The USSR’s effort, the Kola super deep Borehole, is now the deepest hole on Earth. “Well to hell” reaches 7.5 miles underground and took 24 years to accomplish. They wanted to go deeper, but temperatures hotter than 350 °F compromised equipment. There were scientific purposes to this challenge in addition to bragging rights. Researchers were baffled by the presence of liquid water miles below the surface. They believe this is from hydrogen and oxygen atoms being squeezed out of rock layers. They also found fossilized plankton, a whopping 2 billion years old. Despite being 4,000 miles short of hitting the Earth’s core, the borehole was capped in 1994. Japan wants to take Russia’s title with a new drilling project set to kick off in 2030. It aims to dive 3.7 miles under the ocean’s floor into the Earth’s liquid mantle layer.

You might not know these women by name, but their groundbreaking accomplishments definitely deserve your attention.