Magnetometer

A Magnetometer measures the Earth's magnetic field. Earth's magnetism varies from place to place. Differences in the Earth's magnetic field (the magnetosphere) can be caused by a couple things.

1. The differing nature of rocks
2. The interaction between charged particles from the sun and the magnetsophere.

Magnetometers are used in geophysical surveys to find deposits of iron because they can measure the magnetic pull of iron. A Magnetometer can also be used by satellites like GOES to measure both the magnitude and direction of the earth’s magnetic field.

Magnetometers are very sensitive, and can give an indication of possible auroral activity before one can even see the light from the aurora.