Earth has its own vertical world. Above us is the sky; below it are layers of rock accumulated over billions of years, holding fossils, minerals, heat and secrets that humans can reach only by cutting into the ground.
On the Kola Peninsula, near Russia's border with Norway, the Soviet Union tried to go farther down than anyone had gone before. In 1970, the Cold War was pushing the superpowers upward into space, but the mighty Soviets also wanted to conquer what lay beneath their feet. As the country celebrated the centenary of Vladimir Lenin's birth, engineers began drilling into the Earth's crust.
