When the Van Allen belts were first discovered in the 1950s they were thought to be relatively stable structures, but subsequent observations have shown they are dynamic and mysterious. During the occurrence in 2013 the outer belt was certainly not as calm as expected. Two unusual phenomena occurred: a long-lasting electron drop in the Earth’s radiation belts, and large oscillations in the magnetic field.
The results revealed valuable information of unexpected and dramatic changes in the radiation belts allowing scientists to explore the effect of similar conditions around other Earth-like planets at other stars. This type of interaction between the Sun and a planet rarely happens for Earth but it’s believed to be a frequent occurrence for other Earth-like extrasolar planets. Since the closest of these extrasolar planets is several light years away, these measurements help give us a sense of the radiation conditions that might be occurring around some of those distant worlds, that will probably not be visited in our lifetime.
Unlocking these mysteries could be valuable for newer technologies like telecommunication and GPS satellites, which spend most of their time in the Van Allen belts.
Credit for featured image at top of page:
NASA/Van Allen Probes
 "Earth’s magnetosphere and outer radiation belt under sub-Alfvénic solar wind" - Noé Lugaz, Charles J. Farrugia, Chia-Lin Huang, Reka M. Winslow, Harlan E. Spence & Nathan A. Schwadron - Nature Communications - October 3, 2016 - DOI: 10.1038/ncomms13001 - OPEN ACCESS