About 1,800 miles beneath the surface, Earth's internal structure changes abruptly where the solid rock of the mantle meets the swirling molten iron of the outer core. But the boundary between the ...

The Earth’s inner core, a solid sphere predominantly composed of iron and nickel, occupies a central role in our planet’s evolution and geodynamo processes. Although hidden beneath thousands of ...

The center of Earth lies around 4,000 miles under our feet — but what lies beneath the outer crust and the inner core? When you purchase through links on our site, we may earn an affiliate commission.