NASA's Van Allen Probes mission has discovered a previously unknown third radiation belt around Earth, revealing the existence of unexpected structures and processes within these hazardous regions of space.
Earth's radiation belts were one of the first discoveries of the Space Age. A new finding published in Thursday's issue of Science shows that "we still have much to learn about them."
Previous observations of Earth's Van Allen belts have long documented two distinct regions of trapped radiation surrounding Earth. Particle detection instruments aboard the twin Van Allen Probes, launched on August 30, quickly revealed to scientists the existence of this new, transient, third radiation belt.
Back in the 1950s when the radiation belts were discovered, they had little effect on ordinary people. Today the radiation belts are crucial to "our high-tech society." Hundreds of satellites used for everything from weather prediction to GPS to television routinely skim the belts, subjecting themselves to energetic particles that can damage solar panels and short-circuit sensitive electronics. During geomagnetic storms when the belts are swollen by solar activity, whole fleets of satellites can be engulfed, imperiling the technological underpinnings of daily life on the planet below. The Van Allen Probes directly address these down-to-Earth problems.
The new high-resolution observations by the Relativistic Electron Proton Telescope (REPT) instrument, part of the Energetic Particle, Composition, and Thermal Plasma Suite (ECT) aboard the Van Allen Probes, revealed there can be three distinct, long-lasting belt structures with the emergence of a second empty slot region, or space, in between.
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.
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.
by RTT Staff Writer
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