Washington: NASA scientists have discovered a massive particle accelerator in the heart of one of the harshest regions of near-Earth space, known as the Van Allen radiation belts.
The region is of super-energetic, charged particles surrounding the globe.
New results from NASA`s Van Allen Probes show that the acceleration energy is in the belts themselves.
Local bumps of energy kick particles inside the belts to ever-faster speeds, much like a well-timed push on a moving swing.
Knowing the location of the acceleration within the radiation belts will help scientists improve predictions of space weather, which can be hazardous to satellites near Earth.
"Until the 1990s, we thought the Van Allen belts were pretty well-behaved and changed slowly," Geoff Reeves, lead author on the paper and a radiation belt scientist at Los Alamos National Laboratory in Los Alamos, N.M, said.
"With more and more measurements, however, we realized how quickly and unpredictably the radiation belts change. They are basically never in equilibrium, but in a constant state of change," he said.
In order for scientists to understand such changes better, the twin Van Allen Probes fly straight through this intense area of space.
One of the top priorities for the mission, launched in August, is to understand how particles in the belts are accelerated to ultra-high energies.
The findings are published in the journal Science.