If you were to slice through it, you would see the Earth is divided into distinct layers. On top is the relatively thin crust where we live. Beneath that is the 2,900 km thick mantle layer. Then, enclosed within the mantle is the innermost metallic core of our planet.

The mantle is Earth’s largest layer of rocks. However, because it is covered by at least six kilometres of crust, drilling into it has not generally been possible. The only exception has been where the mantle is exposed by faulting, where a crack forms in the Earth’s crust.