* Thickness: 5-70 kilometers

* Composition: Solid rock

* Temperature: Up to 1,200 degrees Celsius (2,200 degrees Fahrenheit)

The crust is the outermost layer of the Earth. It is made up of solid rock that is mostly composed of oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium. The crust is divided into two main types: continental crust and oceanic crust. Continental crust is thicker and less dense than oceanic crust. It is found on the continents and is made up of a variety of rocks, including granite, sandstone, and limestone. Oceanic crust is thinner and denser than continental crust. It is found on the ocean floor and is made up of basalt, a dark, fine-grained rock.

Mantle

* Thickness: 2,900 kilometers

* Composition: Solid rock

* Temperature: Up to 3,700 degrees Celsius (6,700 degrees Fahrenheit)

The mantle is the layer of the Earth beneath the crust. It is made up of solid rock that is mostly composed of oxygen, silicon, magnesium, iron, and calcium. The mantle is very hot and is constantly moving. The movement of the mantle is what causes the Earth's continents to drift.

Outer core

* Thickness: 2,260 kilometers

* Composition: Liquid iron and nickel

* Temperature: Up to 5,700 degrees Celsius (10,300 degrees Fahrenheit)

The outer core is the layer of the Earth beneath the mantle. It is made up of liquid iron and nickel. The outer core is very hot and is constantly moving. The movement of the outer core is what generates the Earth's magnetic field.

Inner core

* Thickness: 1,220 kilometers

* Composition: Solid iron and nickel

* Temperature: Up to 6,000 degrees Celsius (11,000 degrees Fahrenheit)

The inner core is the innermost layer of the Earth. It is made up of solid iron and nickel. The inner core is very hot and is extremely dense. The pressure at the center of the inner core is estimated to be over 3.6 million times greater than the pressure at sea level.