Eaths Crust and Scale

Plasma physicists have made an unprecedented measurement in their study of the Earth's magnetic field. Thanks to the European Space Agency's Cluster satellites they detected an electric field thought to be a key element in the process of 'magnetic reconnection'.
Thanks to these measurements, obtained by the eight PEACE electron sensors onboard the four spacecraft, scientists now have their first insight into magnetic reconnection's detailed behaviour.
The Earth's magnetic field creates a buffer zone, the magnetosphere, between our planet's atmosphere and the particles released during these eruptions. The Sun also releases a steadier flow of charged particles called the solar wind. On the large-scale, any heading this way buffet the magnetosphere, and are deflected by it. Plasma physicists describe this behavior with a theory called 'magneto-hydrodynamics' (MHD).
On smaller scales, however, the picture becomes rather more complicated. The particles can actually flow across the magnetic field lines. This makes the mathematics of the behavior more difficult. First to misbehave are the ions (positively charged particles). These break away from simple MHD on scales of less than a few hundred kilometers. On even smaller scales, less than 10 kilometers, the electrons (negatively charged particles) begin playing by other rules, too.

Anthony Vena