A Peek Inside Our Planet  
The Earth's layers The Earth is made of different layers.

We live on the Earth's crust, a layer of rock about 30 kilometers (22 miles) thick. That might seem thick, but it's actually very thin, considering the size of the Earth. The Earth's crust and some of the mantle below is broken up into large pieces called tectonic plates.

The mantle is a thick layer just under the crust. It's as hard as rock, but it's actually flowing very slowly, about as slowly as your fingernails grow.

The outer core is a liquid layer, made mostly of iron and nickel, that moves around the inner core. This motion causes the Earth to act like a giant magnet.

The inner core is a solid ball made almost entirely of two metals, iron and nickel. It's hotter here than on the surface of the Sun!