'Within mere days of launch, the Van Allen Probes showed scientists something that would require rewriting textbooks.'Īn artist's depiction of the two Van Allen probes orbiting Earth. 'Then something happened no one had ever seen before: the particles settled into a new configuration, showing an extra, third belt extending out into space,' the agency added. 'It was a lucky decision,' NASA said in February 2013, noting that a solar storm had already caused the radiation belts to swell as soon as the instrument was turned on. Usually, scientists take a few months after launch to calibrate their instruments, but a team with the Relativistic Electron Proton Telescope asked that their instrument be turned on almost immediately (three days after launch) they wanted to compare observations before another mission, SAMPEX (Solar, Anomalous, and Magnetospheric Particle Explorer), de-orbited and entered Earth's atmosphere. However, fuel reserves are running low and the probes will likely retire in the next couple of years. The mission was planned to last two years, but as of May 2018 the probes were still operating at more than double the expected mission lifetime.

The Van Allen Probes (formerly known as the Radiation Belt Storm probes) have several scientific goals, including discovering how the particles - ions and electrons - in the belts are accelerated and transported, how electrons are lost and how the belts change during geomagnetic storms.

So scientists are interested in close study of this region.

Allen datagraph belt change long