Seismic waves are shock waves that propagate through Earth's layers after an earthquake or explosive event, traveling at different speeds depending on the density and state of the material.

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 ...

Scientists have always been curious about the atmosphere surrounding us, but in the past, they could not just hop on a spaceship to see what was up there. Instead, scientists hiked up high ...