UCLA scientists have discovered a new source of super-fast, energetic electrons raining down on Earth, a phenomenon that contributes to the colorful Aurora borealis but also poses dangers to satellites, spacecraft and astronauts.
The researchers observed unexpected, rapid andelectron precipitation from low-Earth orbit using the ELFIN mission, a pair of tiny satellites built and operated on the UCLA campus by undergraduate and graduate students guided by a small team of staff mentors.
The sudden downpour was caused by whistler waves, a type of electromagnetic wave that ripples through space and affects electrons in the Earth's magnetosphere, according to the scientists.
Their findings, published in the journal Nature Communications, show that whistler waves are responsible for a lot of electron rain.
The mission is yielding new insights due to its unique vantage point.
The Van Allen radiation belts are filled with charged particles and are located around the planet. These belts are like spirals that bounce between the north and south poles. Whistler waves are generated within the radiation belts and can be used to speed up the electrons. The electrons fall out of the belts and into the atmosphere, creating the electron rain.
Vassilis Angelopolous, a UCLA professor of space physics, said that one can imagine the Van Allen belts being filled with water or electrons. As the basin gets bigger, the water goes into a relief drain to keep it from overflowing. The water spills over the edge faster and in greater volume than the relief drainage when large waves occur. The contributions from both flows are measured by ELFIN, which is downstream of both flows.
The team was able to understand the process by which the waves cause rapid torrents of electrons to flow into the atmosphere thanks to the low-altitude electron rain measurement by ELFIN.
The findings are important because current theories and space weather models don't predict the extra whistler wave, which can affect Earth's atmospheric chemistry.
The researchers showed that the type of radiation-belt electron loss to the atmosphere can increase significantly during geomagnetic storms.
The two are inextricably linked and can benefit satellites and astronauts passing through the region.
More than 300 UCLA students have worked on an experiment funded by NASA and the National Science Foundation. The two microsatellites, each about the size of a loaf of bread and weighing roughly 8 pounds, were launched into the sky in the fall of 2018, and since then have been observing the activity of energetic electrons and helping scientists to better understand the effect of magnetic storms. The UCLA Mission Operations Center is where the satellites are operated.
Colin Wilkins, a co-author of the current research who is the instrument lead on ELFIN and a space physics PhD student, said it was rewarding to have increased our knowledge of space science using data from the hardware we built ourselves.
More information: Xiao-Jia Zhang et al, Superfast precipitation of energetic electrons in the radiation belts of the Earth, Nature Communications (2022). DOI: 10.1038/s41467-022-29291-8 Journal information: Nature Communications Citation: Researchers discover source of super-fast electron rain (2022, March 30) retrieved 30 March 2022 from https://phys.org/news/2022-03-source-super-fast-electron.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
All Rights Reserved © 2024
