Earth's core separates
Molten iron sinks to the centre, and the planet sorts itself into layers.
- When
- Known to
- ± 20 million years
- Era
- Hadean
In a largely molten Earth, dense iron and nickel drain inward while lighter silicates rise, producing the metallic core and rocky mantle. Hafnium-tungsten isotope systematics date the process to within roughly 30 million years of the Solar System's formation. The energy released by that separation heats the planet further, and the core it produced is what later drives the magnetic field.