Science
How does Earth's magnetic field work?
Earth's magnetic field is generated deep inside the planet, where the swirling molten iron of the outer core acts like a giant dynamo. This churning, electrically conductive metal creates electric currents that produce a magnetic field stretching far into space.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how Earth's magnetic field works.
Step by step
- 1It's generated by Earth's molten iron outer core.
- 2Moving, conductive metal acts like a dynamo.
- 3This produces a field reaching far into space.
- 4It guides compasses and shields us from solar wind.
Frequently asked questions
- How does Earth's magnetic field work?
- Churning molten iron in Earth's outer core acts as a dynamo, generating the planet's magnetic field.
- Why does a compass point north?
- Its needle aligns with Earth's magnetic field, which runs roughly between the magnetic poles.
- Does Earth's magnetic field ever change?
- Yes — it drifts, weakens and strengthens, and has even flipped poles many times over geological history.