•         Earth has an immense magnetic field surrounding it, just as there is a magnetic field around a bar magnet.

•         Earth’s magnetic poles are not located at the geographic poles.

•         The angle between geographic north and magnetic north (the north to which a compass needle points) is known as magnetic declination.

•         Magnetic declination changes over time because the magnetic poles are slowly moving.

•         Earth’s magnetic fields extend into space, which contains electrically charged particles.

•         Earth’s magnetic field affects the movements of electrically charged particles in space.

•         Charged particles also affect Earth’s magnetic field.

•         Sources of electrically charged particles that affect Earth’s magnetic field are:

–        Van Allen Belt: Two regions between 1000 and 25000 Km above Earth’s surface containing electrons and protons moving at very high speeds.

•         Sources of electrically charged particles that affect Earth’s magnetic field are:

–        Solar Wind: A stream of electrically charged particles flowing at high speeds from the sun.

–        Earth and other planets experience a solar wind.

–        The solar wind pushes against Earth’s magnetic field and surrounds the field.

–        The region of Earth’s magnetic field shaped by the solar wind is called the magnetosphere.

•         The region of Earth’s magnetic field shaped by the solar wind is called the magnetosphere.

•         When charged particles get close to Earth’s surface, they interact with atoms in the atmosphere.

•         This causes the atoms to give off light.

•         A glowing region caused by charged particles from the sun is called an aurora. In the Northern Hemisphere, an aurora is called the Northern Lights.

•         Since Earth produces a strong magnetic field, Earth itself can make magnets.

•         Earth’s magnetic field also acts on rocks that contain magnetic material.

•         Magnetic Rock in Grand Marais, MN

•         Earth can leave a magnetic history of itself

–        Molten material seeps up through the ocean floor.

–        When it is molten, the iron it contains lines up in the direction of Earth’s magnetic field.

–        As the rock cools and hardens, the iron is locked in place.

•         Why does Earth’s magnetic field change direction?

–        Earth’s magnetic field arises from the motion of the molten metal in the Earth’s core.

–        Changes in the flow of that metal result in changes in Earth’s magnetic field.

–        Details of this theory have not yet been worked out!