In 2000, the European Space Agency sent four spacecraft into the magnetosphere, to study how the magnetic field around the planet works. For a decade, the craft have analyzed the aurora, solar winds, and more. How do they do it?

In 2000, FM5-FM8 were put into orbit, each armed with 11 instruments to measure the magnetosphere in 3D. By repositioning the crafts, researchers can read across a wide variety of scales, from tens of thousands of kilometers, down to just tens.

The spacecraft measure effects that solar winds have on the magnetosphere, and the protection it offers us from being bombarded by deadly particles from solar storms. These storms create the aurora borealis and australis; ionospheric disturbances; radiation belts; and the disturbance of magnetic fields at ground level.

Because there are four craft in the magnetosphere, all their experimental results are recorded in three dimensions. What have they observed? The wide variety of sensors have given the mission a laundry list of accomplishments . For instance, there's the Plasma Electron and Current Experiment (PEACE), which is used to analyze the 3D distribution of electrons in plasma. More specifically, it's been used to study what the ESA describes as

"...bubbles of plasma three times the size of Earth jetting through the magnetosphere, very thin sheets of electric current flowing through space where explosive magnetic reconnection occurs, and grand waves on the edge of the magnetosphere, formed by the solar wind 'blowing' over the surface before breaking and forming tornado-like vortices."

In 2004, China and the ESA teamed up to put another two into space, in order to bolster the study and provide even more information.

Top image by Arctic Norway. Other images via University College London