Supercharging the Radiation Belts

On March 17, 2015, an interplanetary shock – a shockwave created by the driving force of a coronal mass ejection, or CME, from the sun – struck the outermost radiation belt, triggering the greatest geomagnetic storm of the preceding decade. NASA’s Van Allen Probes were there to watch it. One of the most common forms of space weather, a geomagnetic storm describes any event in which Earth’s magnetic environment – called the magnetosphere – is suddenly, temporarily disturbed. Such an event can also lead to