spacetoday.net: NASA spacecraft detect third, temporary Van Allen radiation belt

Posted: Fri, Mar 1, 2013, 7:10 AM ET (1210 GMT)
Van Allen Probes illustration (NASA)

A pair of NASA spacecraft launched last year have detected for the first time a third, and temporary, belt of radiation girdling the Earth as part of the Van Allen belts, scientists announced Thursday. NASA's twin Radiation Belt Storm Probes, renamed the Van Allen Probes after their launch last August, detected this new, transient belt shortly after launch. The belt remained in place until a shock wave from the Sun swept it away four weeks later. The existence of this third belt came as a surprise to scientists who had previously only seen two radiation belts and had not even theoretically considered the existence of a third belt. Scientists speculate that a solar storm around the time of the probes' launch may have created the temporary third belt.