What is a magnet? A magnet is an object that has a magnetic field. This field cannot be seen. It gives the magnet its special abilities. The magnet can pull on metal materials. The magnet can attract or repel other magnets.

Magnets have two poles. The poles always come in pairs. They cannot be separated. Opposite poles repel each other. Like poles attract each other.

Can you guess what is the biggest magnet on Earth? Here’s a hint. A magnet’s two poles are called the north pole and the south pole. Does that sound familiar? That’s right – the biggest magnet on our planet is the Earth itself!

The Earth has a shallow crust that covers a thick mantle of rock. Under the mantle there is a core of liquid metal. Under the liquid is a solid metal center. The metal is mostly iron.

The movement of electrical charges in the Earth’s core create its magnetic field. The field surrounds the Earth for thousands of miles. The field blocks radiation from the sun. If the field did not exist, the radiation would kill all the life on Earth.

It is good that the Earth has a magnetic field. But it is also good that the Earth’s magnetic field isn’t very strong. If it were, all of our metal objects would be pulled to the North Pole!