Inside the belly of planet Earth, a giant solid ball of metal is surrounded by a swooshing layer of liquid iron and nickel ... might migrate into the rocky mantle, the next geological layer ...

a 1,400-mile-thick band of iron and nickel fluids. Beyond the outer core lies the mantle, a 1,800-mile-thick layer of viscous molten rock on which Earth's outermost layer, the crust, rests.

The iron isn't pure—scientists believe it contains sulfur and nickel ... and the lower mantle. The boundary between the two lies about 465 miles (750 kilometers) beneath the Earth's surface.

And the inner core is made of solid iron and nickel. The surface of the earth is constantly changing. It's the movement of the mantle that causes the tectonic plates to rub together on the surface ...

New research led by a York University professor sheds light on the earliest days of Earth's formation and potentially calls ...

Earth’s core could contain helium from the early solar system. The noble gas tucks into gaps in iron crystals under high pressure and temperature.

By analyzing seismic waves from earthquakes from the 1960s, researchers from Peking University deduced that the Earth's inner core has experienced a b ...