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 ...

There's a lot more to Earth than meets the eye. Far from being just a roundish rock barreling through space, our planet is composed of several layers held together by intense forces of gravity.

Crust The crust is the outer layer of the Earth on which we live. It is the thinnest layer and is between 5 and 90 km thick. Earth is divided into four layers: the inner core, the outer core ...

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 ...