That Time The U.S. Tried To Drill The World’s Deepest Hole

*Geologist Dr. Harry Hammond Hess lectures about Project Mohole at Princeton University in 1961.*

There’s a mystery hiding deep beneath our feet. If you dig down past the tree roots and house foundations, past the water table and the fossilized bones, through layers of rock and ore, you’ll eventually reach a boundary. Here, the Earth’s crust — the rock we live our lives on — transitions into the denser rock of the Earth’s mantle. This boundary is the Mohorovičić discontinuity, or “Moho” for short. And no one knows for sure what this boundary looks like, or what lies there.

Sixty years ago, scientists tried to solve that mystery. They wanted to reach the Moho by drilling the world’s deepest hole at the bottom of the ocean — a project that journalists compared to a moon shot at the time. The scientists thought, if they could just pull up a cross-section of this Moho, they might uncover secrets about the Earth’s inner workings…. read more >