We've talked about measuring the Earth's magnetic field from the ground, but we can also measure it with satellites.

A magnetometer measures the strength of the magnetic field around it		We fly magnetometers on spacecraft - and they are pretty sophisticated pieces of equipment. They not only detect the strength of the magnetic field around the spacecraft but they can also detect its direction and any oscillations in it.


The Cluster II mission is a set of four satellites in orbit around the Earth. Together they give us a full 3-d look at the magnetosphere and the waves within it. Here’s an artist’s impression of the Cluster II satellites in space.