Holes stories

Geologists will try and tell you that it's easier to explore the moon and Mars than it is to explore the Earth's mantle. As a geologist myself, I think they're full of it, but they do have a point that we don't know a whole heck of a lot about what's going on beneath our feet. To find out, an international team wants to drill into Earth's mantle, 3.7 miles below the ocean.