Particles zipping around Earth at near light-speed finally explained

[Judi Lynn]

By Stephanie Pappas - Live Science Contributor 7 hours ago

The electrons are trapped in an endless loop around the planet.



An illustration of Earth's Van Allen belts, with the trajectories of ultra-relativistic electrons in gray. The colorful loops in the foreground are the orbits of satellites that must pass through this electromagnetically dangerous area of space.
(Image: © Ingo Michaelis & Yuri Shprits, GFZ)

In the swirl of a perfect solar storm, electrons can get trapped near Earth, where they can accelerate to nearly the speed of light.

These electrons get their zip from surfing on waves of super-heated, charged gas called plasma that gets launched from the sun during solar storms. They accelerate to near-light speed, though, only when the plasma density is low, according to a new study led by researchers from the GFZ German Center for Geosciences in Potsdam.

The findings are important because electrons traveling so quickly are particularly dangerous to satellites and other electronic equipment. They can penetrate the shielding that protects satellites from other charged particles in solar storms, damaging sensitive components.

The phenomenon occurs in the two Van Allen radiation belts, which are loops of charged particles trapped in a kind of donut shape around Earth. The belts, which extend from about 400 miles to more than 36,000 miles (640 to 58,000 kilometers) above Earth's surface, protect our planet from charged particles emanating from the sun. But they also react to solar storms in ways that aren't fully understood. In 2012, NASA launched two Van Allen Probes to take measurements in this mysterious zone of near-space. The probes detected electrons at "ultra-relativistic energies" — in other words, traveling near the speed of light.

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https://www.livescience.com/van-allen-electrons-ultra-relativistic.html