Core of the Worlds

If you're like the Mole Man of Hackney (not to be confused with Mole Man the Marvel villain), you love to dig deep into the core of the issues that matter to you. For example, how do scientists know that the earth is made up of crust, mantle, and core? How do they REALLY KNOW it's not hollow or full of dirt and rocks all the way through? Get the dirt in this week's installment of Nerd Nite Nostalgia!