Scientists unraveling mysteries of Earth’s Van Allen radiation belts
Washington – Researchers are unraveling the longstanding mysteries surrounding the Van Allen radiation belts that circle Earth.
The discovery used measurements taken by a University of New Hampshire-led instrument on board NASA’s Van Allen Probes twin spacecraft to reveal that the high-energy particles populating the radiation belts can be accelerated to nearly the speed of light.
This mode of action is analogous to that of a particle accelerator like the Large Hadron Collider.
However, in this case, the Earth’s vast magnetic field, or magnetosphere, which contains the Van Allen belts, revs up drifting electrons to ever-higher speeds as they circle the planet from west to east.
Co-author Harlan Spence, director of the UNH Institute for the Study of Earth, Oceans, and Space, principal scientist for the ECT, said that the acceleration they first reported operates on the scale size of an electron’s gyromotion — it is a really local process, maybe only a few hundred meters in size.
He said that they’re we’re seeing this large-scale, global motion involving ultra low-frequency waves pulsing through Earth’s magnetosphere and operating across vast distances up to hundreds of thousands of kilometers.
Spence asserted that with the Van Allen Probes, I like to think there’s no place for these particles to hide because each spacecraft is spinning and ‘glimpses’ the entire sky with its detector ‘eyes’, so we’re essentially getting a 360-degree view in terms of direction, position, energy, and time.
The discovery has been published in the journal Nature Communications.