Earth & climate
Earth's magnetic field
An invisible shield around the Earth that guides the compass and paints auroras in the sky.
The Earth is surrounded by something you cannot see or touch and that is enormously important all the same: the . It works like a giant invisible shield. A compass shows it to you, colourful in the sky reveal it, and without this field life on Earth would be in great danger.
A magnet deep inside
Deep inside the Earth sits a core of iron: solid in the middle, liquid around it and close to 6,000 degrees hot at its centre. In the liquid part the iron keeps flowing, and that flow generates the magnetic field. It reaches far out into space and wraps around the whole planet. So you can picture the Earth like a huge bar magnet, with one magnetic pole near the geographic north pole and one near the geographic south pole.
The shield against the solar wind
From the Sun comes a constant stream of tiny charged particles, the . These particles are harmful to living things. The magnetic field steers most of them around the Earth, just as a rock splits the water of a river. Only at the poles do some particles enter the air and make it glow. This is how the auroras in green, red and violet come about.
up to about 500 °C. Thin solid outer shell, we live on it.
The compass finds north
A compass needle is itself a small magnet. It lines up with the Earth's magnetic field and points almost exactly north. Only almost, because the magnetic pole does not sit exactly at the geographic north pole and wanders a few dozen kilometres further every year. Even so, seafarers many hundreds of years ago could find their way with the compass, even when clouds hid the stars. Today too, hikers and pilots use this simple and reliable principle.
Exercises
0 of 6 solvedTime to try it yourself. You can't break anything, every attempt counts.
Where is the Earth's magnetic field created?
What does the Earth's magnetic field protect us from?
A magnet always has 2 poles. How many poles do 4 separate magnets have together?
The Earth's magnetic field is created by moving, hot … deep in the planet's core.
You turn all the way around once with the compass, from north past east and south back to north. By how many degrees have you turned?
Match each term about the Earth's magnetic field with the description that fits.