. . .While the most immediate practical need for studying the radiation belts is to understand the space weather system near Earth and to protect humans and precious electronics in space from geomagnetic storms, there is another reason scientists are interested in this area. http://www.messagetoeagle.com/electratmospheplasma.php
It is the closest place to study the material, plasma, that pervades the entire universe. Understanding this environment so foreign to our own is crucial to understanding the make up of every star and galaxy in outer space.