One of the three parts of Earth, the outer core, is about 1,430 miles (2,300 kilometres) thick and has a temperature between 7,200 and 9,000 F. National Geographic says that the outer core is mostly made up of iron and nickel in the form of a liquid alloy.
The outer core is the middle layer of the three layers that make up the Earth. It is about 1,800 miles below the Earth’s crust, which is the topmost surface. The hottest part of the Earth is the inner core, which is also the deepest part. The outer core surrounds the inner core and touches the mantle, which is the third region and the one closest to the Earth’s crust. The outside and inside cores are almost entirely made of nickel and iron. The solid core is inside, while the liquid core is on the outside. Unlike the inner core, the pressure on the outer core is not strong enough to make it solid. Instead, it stays in the form of a liquid around the inner core. But the outer core’s liquid metal form is also caused by the fact that it is very hot—about four times hotter than lava. The magnetic field in the outer core is also about 50 times stronger than the one at the surface of the Earth.