In the 1970s, Soviet scientists drilled the Kola Superdeep Borehole in Siberia, reaching a depth of 12 kilometers—the deepest hole ever drilled by humans. Instead of expected rock conditions, they encountered Venus-like temperatures exceeding 180°C, far hotter than predicted. Even more unsettling were reports of strange unexplained sounds picked up by instruments deep underground, fueling decades of mystery and speculation. Important Details: • Drilled to 12 km depth • Temperatures exceeded pred