The Earth has a huge magnetic field and all magnetic objects, such as the compass needle, get oriented to it. One end of the freely rotating compass needle marked in colour aligns itself with the north pole of the Earth. This helped the early explorers to find their ways in oceans. Near the poles they often saw an impressive phenomenon in the sky known as aurora. Moreover, a lot of things would not have existed today without strong magnets called electromagnets that can be switched on and off.
