As remarkable as it may seem, we actually know more about certain distant galaxies than we do about what lies beneath the Earth’s surface. Exploring what’s under our feet is surprisingly complex. In the 1970s, Soviet scientists were determined to probe deeper into the Earth’s crust—drilling on and off for 24 years.
The Kola Superdeep Borehole, with a drill depth of more than 7.5 miles, is the result of their efforts. The hole, which is located on the Kola Peninsula of Russia, descends further than the deepest point of the ocean (6.8 miles).
The Soviet efforts also yielded some pretty significant scientific discoveries. Microscopic fossils of single-celled organisms were found 4.3 miles below the Earth’s crust—which is also where water was discovered. The temperature at the bottom of the hole reached 356 degrees. It was this blistering heat that halted the drilling in 1994.
One of the most shocking conclusions from the journey to the center of the earth is that scientists estimate it to be 4,000 miles down. In more than two decades, we’ve only scratched the surface.