Starting at the surface, you would have to dig nearly 2,000 miles before reaching the Earth’s core. No one could survive that trip – and the 10,000-degree F heat once there would vaporize you anyway.
Mountains can’t be created without lubricant, and 2 billion years ago that lubricant was graphite produced by the carbon broken down from layers of dead plankton on the ocean floor.
Earth hasn’t always been a blue and green oasis of life in an otherwise inhospitable solar system. During our planet’s first 50 million years, around 4.5 billion years ago, its surface was a hellscape of magma oceans, bubbling and belching with heat from Earth’s interior.
The subsequent cooling of the planet from this molten state, and the crystallisation of these magma oceans into solid rock, was a defining stage in the assembly of our planet’s structure, the chemistry of its surface, and the formation of its early atmosphere.
These primeval rocks, containing clues that might explain Earth’s habitability, were assumed to have been lost to the ravages of plate tectonics. But now, my team has discovered the chemical remnants of Earth’s magma oceans in 3.7 billion year-old rocks from southern Greenland, revealing a tantalising snapshot of a time when the Earth was almost entirely molten.