Balloons Flying Over Antarctica May Help Solve Radiation Mystery

The planet is surrounded by two gigantic, fluctuating donut-shaped zones made of protons and electrons known as the Van Allen radiation belts. The charged particles in these zones can damage sensitive electronics on spacecraft such as those used for global positioning systems (GPS) and communications and can injure humans in space.
"Probably the most interesting thing to me about the radiation belts is how variable the region is," physicist Robyn Millan at Dartmouth College told SPACE.com. "During geomagnetic storms, we see charged particles accelerated to really high, relativistic energies,  near the speed of light. The number of these particles can increase by a factor of 1,000 in a day or less. We don't often think of Earth as being an efficient particle accelerator like exotic objects such as black holes or supernovae, but it is, and it is right in our own backyard, so we can really study the processes in detail."

"Equally as exciting as the particle acceleration are the rapid depletions of the radiation belts that we observe," Millan added. "The entire radiation belts can nearly disappear in the matter of a day or even less."