Searching for ‘Dark Oxygen’ in One of the World’s Deepest Mines | Atlas Obscura

Emil Ruff was about to travel into the center of the Earth. Wearing safety goggles, a protective suit, a helmet, and sturdy work boots, he was crammed in a large metal cage with his colleagues, along with several dozen miners on their morning shift, to descend down the world’s deepest single-shaft elevator. His ears popped as the elevator plunged downward at 60 kilometers per hour (37 mph). The lift made stops along the way. First one kilometer down. Then two. The elevator descended further. The air got hotter.

Finally, at around 3 kilometers (nearly 2 miles), a mere four minutes later, Ruff and his team got off. After a short train ride, they reached a rocky tunnel that looked a lot like Mars, which is exactly what brought Ruff to these depths. He’s a microbiologist at the Marine Biological Laboratory in Woods Hole who studies organisms deep below Earth’s surface as a way to understand the possibility of life in the cosmos. Ruff is particularly interested in how microbes produce so-called “dark oxygen,” or oxygen found in the absence of light. A couple of years ago, he found microorganisms that appeared to have this ability in aquifers in Canada, a couple hundred meters below Earth’s surface. “And so then I was wondering, well, how deep can you go and still find these organisms?” he says. Read rest of the article here.