My thanks to contributor ‘oldbrew’ for drawing my attention to this Sciencedaily.com article on NASA’s twin Van Allen Probes, which are orbiting in Earth’s most hostile radiation environment.
NASA’s Van Allen Probes Reveal New Dynamics of Earth’s Radiation Belts
Just 96 days since their launch, NASA’s twin Van Allen Probes have already provided new insights into the structure and behavior of the radiation belts that surround Earth, giving scientists a clearer understanding about the fundamental physical properties of these regions more than half a century after their discovery.
Throughout the brief early life of the two-year mission, energetic events and ejections of plasma from the sun caused dramatic changes in the radiation belts that, for the first time, were observed by twin spacecraft within the belts. “The sun has been a driver of these systems more than we had any right to expect,” says Daniel Baker, Principal Investigator
The twin probes…contain identical sets of five instrument suites. These suites have confirmed previous hypotheses about the belts’ behavior, while also revealing that the belts are a far more dynamic and changing environment than previously thought. “We expected to see a fairly placid radiation belt system,” Baker says. “Instead, we see that the belts have been extraordinarily active and dynamic during the first few weeks.
Measurements made by instruments like the Electric Fields and Waves Suite (EFW) and the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) are helping scientists understand how those fields and waves affect the particles. “The electric field and magnetic field measurements on the Van Allen Probes are the best ever made in the radiation belts,” says the University of Iowa’s Craig Kletzing, Principal Investigator for EMFISIS. “For the first time, we’ve been able to see how long intense low frequency electric fields and waves at the edge of the radiation belts can last — sometimes for over five hours during geomagnetic storms.
Read the full story here: