What causes Earth's magnetic field?


Quick Answer

The leading hypothesis is that the earth’s spinning core causes the Earth's magnetic field, but scientists are unsure about the exact mechanism by which it is created. Iron is the primary constituent of the Earth’s core, and it is able to spin because of its layered construction.

Continue Reading
What causes Earth's magnetic field?
Credit: Science Picture Company Collection Mix: Subjects Getty Images

Full Answer

No one has ever drilled or tunneled into the core to observe its function personally, so scientists must use mathematical models to understand planet formation. Scientists believe that the core has two distinct layers. There is a solid inner core and a liquid outer core. Both components exist at very high temperatures and are exposed to very high pressures. This causes the materials to behave differently than they would at the surface.

Because the inner core is solid and has a greater density, it resists spinning as the Earth does. Instead, it remains relatively stationary while the molten iron surrounding the inner core spins with the Earth. Additionally, convection currents arising from the super-hot temperatures contribute to the liquid’s spinning motion.

As the molten iron spins around the solid, crystalized iron inside the inner core, it generates a relatively weak magnetic field. This magnetic field helps to protect the Earth from dangerous types of radiation, and it helps make life possible on the planet.

Learn more about Planets

Related Questions