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 ...

New research is reshaping how scientists understand the earliest days of Earth’s formation—suggesting that the deep interior ...

Seismic waves are shock waves that propagate through Earth's layers after an earthquake or ... surface reveals aspects of the composition and physical properties of the rocks beneath.