idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
idw - Informationsdienst
Wissenschaft
Electrons are locally heated to extremely high energies within the Van Allen Radiation Belts, new study finds
The Earth’s magnetic field is trapping high energy particles. When the first satellites were launched into space, scientists led by James Van Allen unexpectedly discovered the high energy particle radiation regions, which were later named after its discoverer Van Allen Radiation Belts. Visualized, these look like two donut-shaped regions encompassing our planet. Now, a new study led by researchers from GFZ German Research Centre for Geosciences shows that electrons in the radiation belts can be accelerated to very high speeds locally.
The Earth’s magnetic field is trapping high energy particles. When the first satellites were launched into space, scientists led by James Van Allen unexpectedly discovered the high energy particle radiation regions, which were later named after its discoverer Van Allen Radiation Belts. Visualized, these look like two donut-shaped regions encompassing our planet. Now, a new study led by researchers from GFZ German Research Centre for Geosciences shows that electrons in the radiation belts can be accelerated to very high speeds locally. The study shows that magnetosphere works as a very efficient particle accelerator speeding up electrons to so-called ultra-relativistic energies. The study conducted by Hayley Allison, a postdoctoral scholar at GFZ Potsdam, and Yuri Shprits from GFZ and Professor at the University of Potsdam, is published in Nature Communications.
To better understand the origin of the Van Allen Belts, in 2012 NASA launched the Van Allen Probes twin spacecraft to traverse this most harsh environment and conduct detailed measurements in this hazardous region. The measurements included a full range of particles moving at different speeds and in different directions and plasma waves. Plasma waves are similar to the waves that we see on the water surface, but are in fact invisible to the naked eye. They can be compared to ripples in the electric and magnetic field. Recent observations revealed that the energy of electrons in the belts can go up to so called ultra-relativistic energies. These electrons with temperatures above 100 Billion degrees Fahrenheit, move so fast that their energy of motion is much higher than their energy of rest given by Einstein’s famous E=mc2 formula. They are so fast that the time flow significantly slows down for these particles.
Scientists were surprised to find these ultra-relativistic electrons and assumed that such high energies can be only reached by a combination of two processes: the inward transport of particles from the outer regions of the magnetosphere, which accelerates them; and a local acceleration of particles by plasma waves.
However, the new study shows that electrons reach such incredible energies locally, in the heart of the belts, by taking all this energy from plasma waves. This process turns out to be extremely efficient. The unexpected discovery of how acceleration of particles to ultra-relativistic energies operates in the near-Earth space, may help scientists understand the fundamental processes of acceleration on the Sun, near outer planets, and even in the distant corners of the universe where space probes cannot reach.
Media contact:
Josef Zens
Head of press and public relations
josef.zens@gfz-potsdam.de
Phone: +49 331 288-1040
Prof. Dr. Yuri Shprits
Section Head Magnetospheric Physics
E-Mail: yuri.shprits@gfz-potsdam.de
Tel:+49 331 288-28899
Original study: Hayley Allison, Yuri Shprits: “Local heating of radiation belt electrons to ultra-relativistic energies” in “Nature Communications”, DOI: 10.1038/s41467-020-18053-z
Criteria of this press release:
Journalists
Energy, Geosciences, Physics / astronomy
transregional, national
Research results
English
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
