Here's why:
* The Earth's crust is incredibly thick: The crust, the outermost layer of the Earth, can be anywhere from 3 to 40 miles thick.
* Mines are relatively shallow: The deepest mine in the world, the Mponeng Gold Mine in South Africa, reaches a depth of around 2.5 miles.
* The mantle starts far below the crust: The mantle begins at the base of the crust and extends down to about 1800 miles deep.
Even the deepest mines are only scratching the surface of the Earth's crust. Reaching the mantle would require technology far beyond our current capabilities.
