The Earth's interior is composed of four layers, three solid and one liquid—not magma but molten metal, nearly as hot as the surface of the sun. The deepest layer is a solid iron ball ...

Over time, Earth's interior—which is made mostly of silicate rocks and metals—differentiated into four layers. At the planet's heart lies the inner core, a solid sphere of iron and nickel that ...

The Earth is made up of different layers: Therefore, instead of tectonic plates moving because of the convection currents, evidence suggests it is the plates that drive the convection. Slab pull ...