Earth’s Magnetic Field Earth has a moving liquid iron core. A moving conductor creates electric currents. Electric currents make magnetic fields. This causes the Earth to act like a giant bar magnet.

Pouring out of the Sun at 500 Km/s is a huge mass of charged particles, over 1,000,000,000 kilograms per second. This is the solar wind. Our magnetic field stops the solar wind from reaching the Earth.

Four billion years ago, Mars had an atmosphere with oxygen and water vapor and a magnetic field. It lost its magnetic field when its iron core froze. Today, Mars has almost no atmosphere, as it had no protection from the solar wind.

The solar wind hits Earth’s magnetic field and squishes it on the side facing the Sun, and stretches it out on the opposite side.

When solar charged particles (protons and electrons) hit Earth’s air at the poles, they react with the nitrogen and oxygen in our atmosphere and give off light…the aurora (the northern and southern lights.