The Earth's magnetic field is generated by the outer core.
This layer, located deep within the Earth's interior, is composed primarily of molten iron and nickel. The movement of this liquid metal, driven by convection and the Earth's rotation, creates electrical currents. These currents, in turn, generate the magnetic field that surrounds our planet. This process is known as the geodynamo.
Several sources confirm this: The U.S. Geological Survey (https://www.usgs.gov/faqs/how-does-earths-core-generate-a-magnetic-field) explicitly states that the magnetic field is generated in the outer core. Similarly, Space.com (https://www.space.com/earths-magnetic-field-explained) and other reputable sources corroborate this explanation. The movement of molten iron is key; the inner core, while also metallic, is solid and doesn't contribute to the geodynamo in the same way.
The Earth's magnetosphere, a vast region dominated by this magnetic field, protects our planet from harmful solar radiation and cosmic rays.
