Description: Earth has a comparatively simple magnetic field, approximately what physicists call a dipole field, not dissimilar from that of a toy bar magnet. If you suspend a compass needle so that it can move freely in all directions, you can trace the direction of Earth's magnetic field. Near the equator, the field direction is almost horizontal, but as you come closer to Earth's North and South Poles, the direction turns downward. At the so-called magnetic North and South Poles, the compass needle is vertical. The magnetic poles of Earth do not coincide with Earth's geographic poles. They also move around – currently about 50 kilometers per year – an effect that navigators using a compass need to take into account.

Related Terms:

• Earth's Rotation
• Scientific Method
• Magnetic Field
• South Pole

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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