Inner core

The inner core is the Earth's deepest layer, composed mainly of solid iron and nickel. It extends from about 5,150 kilometers (3,200 miles) beneath the surface to Earth's center, about 6,371 kilometers (3,959 miles) down. Despite the extreme heat, the immense pressure keeps it solid. The inner core plays a crucial role in generating Earth's magnetic field through the movement of molten metal in the outer core, which surrounds it. Its properties influence geological processes and the planet’s overall dynamics.