The Russians dug a nine-inch diameter hole 7.5 miles under the ground just to see what was there-until the Earth’s crust started melting their equipment.
The Race to the Bottom
Instead, this was a race to see who could dig the deepest hole into the Earth’s crust. Like kids trying to dig to the other side of the planet to get to China or Australia, but with power tools and the backing of their governments and vastly greater sums of money to support their efforts.
The US kicked off the race in 1961 with Project Mohole, which aimed at reaching the Mohorovičić discontinuity, which is the place where the Earth’s crust meets the mantle.
Over the next five years, the team at Project Mohole succeeded in digging 183 meters (601 feet) down into the Earth’s crust. The impressive part is that they were doing so through 3,566 meters (11,700 feet) of ocean water.