Earth and the Moon

The Magnetic Field

How strong is Earth’s magnetic field?

On typical human scales, it is pretty weak; at Earth’s surface, it is about one gauss in most places. (A refrigerator magnet is typically ten to one hundred gauss.) However, the energy in a magnetic field depends strongly on its volume; so since the field is bigger than our entire planet, overall, Earth’s magnetic power is formidable.


This is a web preview of the "The Handy Astronomy Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App