How deep can we drill?

The deepest drilling in the world is a drill hole on the Russian Kola Peninsula. The hole is 12,262 m deep measured from the ground surface and vertically to the bottom. Although this may sound deep, it only corresponds to scratching Earth’s crust – also known as the lithosphere - slightly. The crust is up to 100 km thick in some places.

The deeper a drill moves into the ground, the higher the temperature and pressure, and the more difficult it is to drill. If the drill head is removed, a deep hole tends to close, as the rock layer around the hole is as soft as modelling wax.