JUN 08, 2021 9:35 AM PDT

Physicists Find Definitive Proof of What Causes the Northern Lights

WRITTEN BY: Annie Lennon

The auroras that are the northern lights have captured the imagination of people for thousands of years. While theories explaining how they came about exist, until now, no one has been able to provide conclusive evidence for these theories. 

For some time, scientists have thought that auroras are produced by powerful electromagnetic waves during geomagnetic storms known as Alfven waves. These waves accelerate electrons towards the Earth’s magnetic field lines in the upper atmosphere where they collide with oxygen and nitrogen molecules. This causes the electrons to enter an excitatory state, after which they relax and emit the lights we know today as auroras.

This theory has been supported by spacecraft missions that have frequently found Alfven waves travelling towards Earth above auroras. But while space-based measurements confirmed this theory, limitations in spacecraft and rocket measurements meant that until now, no definitive test could be conducted to prove that this is how auroras exist.

Now, however, in their new study, researchers were able to conduct a series of experiments at the Large Plasma Device (LPD) in UCLA's Basic Plasma Science Facility. Via their numerical simulations and mathematical models, they were able to show that the results of their experiment agreed with the predicted signature for Landau damping, the phenomenon of electrons ‘surfing’ on the electric field of a wave. 

"This challenging experiment required a measurement of the very small population of electrons moving down the LPD chamber at nearly the same speed as the Alfven waves, numbering less than one in a thousand of the electrons in the plasma," says Troy Carter, one of the authors behind the study.

"The idea that these waves can energize the electrons that create the aurora goes back more than four decades, but this is the first time we've been able to confirm definitively that it works," says Craig Kletzing, co-author of the study. 

"These experiments let us make the key measurements that show that the space measurements and theory do, indeed, explain a major way in which the aurora are created."

 

Sources: EurekAlertNature

About the Author
  • Annie Lennon is a writer whose work also appears in Medical News Today, Psych Central, Psychology Today, and other outlets. When she's not writing, she is COO of Xeurix, an HR startup that assesses jobfit from gamified workplace simulations.
You May Also Like
MAY 04, 2021
Space & Astronomy
Part of a Chinese Rocket is Expected to Fall to Earth Soon
MAY 04, 2021
Part of a Chinese Rocket is Expected to Fall to Earth Soon
In the next few days, part of a rocket that put China's new space station into orbit will fall back to Earth in an uncon ...
JUN 16, 2021
Space & Astronomy
Mapping the Boundaries of the Heliosphere
JUN 16, 2021
Mapping the Boundaries of the Heliosphere
Earth and the planets in the solar system sit within the heliosphere, a giant bubble formed by the charged particles, li ...
AUG 10, 2021
Space & Astronomy
Researchers Confirm Exoplanet at Half the Mass of Venus
AUG 10, 2021
Researchers Confirm Exoplanet at Half the Mass of Venus
An international collaboration of researchers has identified a rocky exoplanet half the size of Venus, making it the low ...
SEP 10, 2021
Space & Astronomy
The Future (and Ethics) of Giant Telescopes
SEP 10, 2021
The Future (and Ethics) of Giant Telescopes
The fate of giant telescopes hangs in the balance as this decade comes to an end.
OCT 18, 2021
Space & Astronomy
Unusual Signals are Emitting From the Direction of the Milky Way's Center
OCT 18, 2021
Unusual Signals are Emitting From the Direction of the Milky Way's Center
An unusual signal has been detected coming from center of the Milky Way - or that direction.
OCT 22, 2021
Health & Medicine
Galactic Cosmic Radiation Could Have Different Effects on Males and Females
OCT 22, 2021
Galactic Cosmic Radiation Could Have Different Effects on Males and Females
As commercial spaceflight becomes readily available, more and more people will have access to space. In decades past, on ...
Loading Comments...