"This is the first time we have had such high-resolution instruments look at time, space and energy together in the outer belt," said Daniel Baker, lead author of the study and REPT instrument lead at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado in Boulder. "Previous observations of the outer radiation belt only resolved it as a single blurry element. When we turned REPT on just two days after launch, a powerful electron acceleration event was already in progress, and we clearly saw the new belt and new slot between it and the outer belt."
Scientists observed the third belt for four weeks before a powerful interplanetary shock wave from the sun annihilated it. Observations were made by scientists from institutions including LASP; NASA's Goddard Space Flight Center in Greenbelt, Md.; Los Alamos National Laboratory in Los Alamos, N.M.; and the Institute for the Study of Earth, Oceans, and Space at the University of New Hampshire in Durham.
Each Van Allen Probe carries an identical set of five instrument suites that allow scientists to gather data on the belts in unprecedented detail. The data are important for the study of the effect of space weather on Earth, as well as fundamental physical processes observed around other objects, such as planets in our solar system and distant nebulae.
"Even 55 years after their discovery, the Earth's radiation belts still are capable of surprising us and still have mysteries to discover and explain," said Nicky Fox, Van Allen Probes deputy project scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "We thought we knew the radiation belts, but we don't. The advances in technology and detection made by NASA in this mission already have had an almost immediate impact on basic science."The Van Allen Probes are the second mission in NASA's Living With a Star Program to explore aspects of the connected sun-Earth system that directly affect life and society. Goddard manages the program. The Applied Physics Laboratory built the spacecraft and manages the mission for NASA.