Usually scientific discovery comes after months and even years of effort, but every now and then someone just gets lucky and has something happen right in front of them. That happened last year when plans were changed for the twin Van Allen satellites that were put into orbit just days before. Typically satellites do not become fully operational after being sent up but are ramped up over months, but the researchers at Goddard Space Flight Center and the University of New Hampshire skipped ahead and caught someone no one had even theorized could happen.
First discovered fifty-five years ago, the Van Allen Belts are areas of intense radiation held in place by the Earth's magnetic field. The radiation is so intense that the belts must be studied for the safety of astronauts that may cross the belts, which is why the Van Allen satellites were created. They are not the first satellites to study the belts though, and one of their predecessors was about to be destroyed, so the researchers prematurely turned on sensors to have some overlap between the new and old satellites. It just so happened that shortly after that a solar storm filled the belts with more radiation and created a completely unexpected third belt.
Though the Van Allen belts have been studied for decades, no theory had predicted conditions that would lead to a third belt being formed, and because of that all future astronomy textbooks will have to be rewritten to reflect that. They will likely be rewritten again once theory explains why this happens.