The deepest hole humans ever dug

Hold to drill. The Kola Superdeep Borehole went 12,262 m into the Kola Peninsula, the deepest hole humans have ever made. Twenty years of drilling, and the bit was only a third of the way through the continental crust.

It stopped in 1992 at 180 C, twice the predicted heat. What came up: water pooled in the granite 3 to 6 km down, drilling mud boiling with hydrogen, plankton fossils at 6 km, and granite where the textbooks promised basalt.

The Well to Hell screams were sound effects from a 1972 horror film. Source lines credited to Courtneys soul on the end card.

Hold to drill.