The Earth itself can generate a huge magnetic field, shielding life on Earth from cosmic rays and allowing the compass to function. On the other hand, the core of the Earth is mainly composed of iron, with temperatures as high as 5500 degrees Celsius, much higher than the Curie temperature of iron. So, why wouldn't the Earth lose its magnetism?

The reason is that the geomagnetic field is not formed by a large magnet. The Earth's core is divided into a molten outer core and a solid inner core, because the pressure of the inner core is much higher than that of the outer core, so although the temperature of the inner core is higher, it does not melt.

Due to the unique structure of the Earth's core, when the Earth rotates, there is a differential rotation between the inner and outer cores. In the outer core, convective iron forms a magnetic field through electromagnetic induction. Therefore, the geomagnetic field can remain in existence under high temperature conditions.