Kola Superdeep Borehole
The opposite of the Space Race you probably don’t know about!
You’ve probably heard of the Space Race; the US and Russia trying to be the first at everything in the goal to explore space. The Russians were winning—the first object, the first person, the first woman put into space by humans. The U.S. couldn’t keep up. So the U.S. started a second race: to the center of the Earth! Well, trying to drill the deepest hole possible, at least.
Obviously, the U.S. didn’t give up on the Space Race and ended up winning when they landed on the moon on July 20, 1969. But the drilling continued. After it was clear that the Russians lost the Space Race, they focused on depth. And in 1989, they reached a depth of 12,262 meters, or 40,239 feet, with the Kola superdeep borehole. That’s over seven and a half miles! At highway speeds, it would take six or seven minutes to drive that far.
Seven miles might not seem like a lot when you’re driving, but when you’re drilling a hole, it’s an insane number. The average oil well goes to less than 2,000 meters, about 6,000 feet. That makes the Kola superdeep borehole six times deeper than oil wells.
So what was learned?
The Earth’s crust, the part we live on and the only part we’ve ever drilled into, changes a lot as you get deeper. The rock changes from what we think of as rock and becomes something more like warm plastic; soft and kind of sticky.
The scientist working on Kola also found microscopic plankton four miles down. How they got there is still a mystery, but most likely there was a sea at that level at one point and a lot of volcanic activity.
What would happen if they went through the crust?
As deep as the Kola superdeep borehole is, it was nowhere near getting through Earth’s crust. The average thickness of Earth’s crust is about nine miles thick, but that takes into account the deepest parts of the ocean. On land where Kola is, the crust is closer to 30,000 meters, or 20 miles, thick. Kola didn’t even make it halfway.
If they had made it through the crust, who knows. Most likely the hole would be plugged with magma before much could happen, or the drill would simply melt before it got close.
Why did they stop?
The project was stopped for the exact reason above: the heat in the hole started making things difficult. The rock was soft and plastic-like. The bits were wearing out. The goal was to go to at least 15,000 meters, but the scientist just couldn’t make it work.
So that’s the story about the deepest hole ever drilled—a response to the Space Race, becoming its own race to see who could go deeper. While much was learned, the cost to keep the project going became too much. And no one has time to throw money into a hole.