Geography & Planet Earth
How many meters deep is the Kola Superdeep Borehole in Russia, the deepest hole humans have ever drilled?
Answer
12,262 meters
It took Soviet engineers almost 20 years to drill, and drilling stopped when the rock became too hot and plastic to bore through. Even so, they only made it about 0.2% of the way to Earth's center.
Source: Smithsonian Magazine
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