Why Earth is a magnet

The idea

Earth behaves like a giant magnet because the movement of liquid iron deep in its core creates electric currents, which generate a magnetic field.

Hanging magnet

In Grade 6 you learnt that a freely hanging magnet rests along the north–south direction.

Why do you think this happens?

• Earth itself behaves like a giant magnet
• The magnet is tired
• The Sun pulls it

Go inside the Earth

Press Next step to follow what happens, from the core to the compass.

A magnet made by currents

The liquid iron in the core keeps moving. This makes electric currents, and electric currents make a magnetic field. So Earth acts like a giant magnet.

The movement of liquid iron in the core creates electric currents, which generate a magnetic field. This is why Earth behaves like a giant magnet.

• Step | What happens
• 1 | Liquid iron in the core moves
• 2 | Electric currents are created
• 3 | A magnetic field is generated

Notes

The movement of liquid iron in the core creates electric currents, which generate a magnetic field, so Earth behaves like a giant magnet.

Check yourself

Earth's magnetic field is generated by …

Why does a freely hanging magnet rest along the north–south direction?

Where is the liquid iron that creates Earth's magnetic field?

Which link between electricity and magnetism explains Earth's magnetism?

• electric currents made by moving liquid iron — correct. Yes!
• a giant bar magnet buried in the ground. The field comes from electric currents made by moving liquid iron in the core.
• the Moon. The Moon has no part in it. It is the core of the Earth.
• The string chooses the direction. A string does not choose a direction. The Earth's magnetic field does.
• Earth behaves like a giant magnet — correct. Yes!
• The wind blows from the north. Wind does not decide it. The Earth's magnetic field does.
• In the clouds. It is deep inside the Earth, in the core.
• In the oceans. It is in the core, not in the oceans.
• In the core, deep inside the Earth — correct. Yes!
• Electric currents produce a magnetic field — correct. Yes!
• A magnet produces heat. That link does not explain it.
• A cell produces light. That link does not explain it.