The mysterious origin of the aurora borealis has been proven


The mystery surrounding the causes of the aurora borealis has been speculated but never proven, until now.

The study showed that these phenomena, also known as Alfvin waves, speed electrons back to Earth, causing the particles to produce the light we know as the aurora borealis.

said Greg Howes, assistant professor in the department. He holds a Ph.D. in physics and astronomy at the University of Iowa and is a co-author of the study.

The idea of ​​electrons “surfing” in an electric field is a theory first introduced in 1946 by Russian physicist Lev Landau, named after Landau damping. His theory has now been proven.

Recreation of the aurora borealis

Scientists discovered decades ago what the aurora borealis might look like, but have now been able to simulate it, for the first time, in the Large Plasma Device (LPD) Laboratory at the University of California’s Primary Plasma Science Facility.

The scientists used a 20-meter chamber to recreate Earth’s magnetic field using powerful magnetic field coils from UCLA’s LPD. Inside the chamber, scientists have produced plasma similar to what is found in near-Earth space.

“Using a specially designed antenna, we shot two thousand waves into the device, just like rocking a garden hose up and down and watching the wave move along the hose,” Howes said. When they began to feel the electrons “surfing” along the wave, they used another specialized instrument to measure how these electrons were drawing energy from the wave.

The aurora borealis appear over a waterfall in Iceland.

Although the experiment did not recreate the colored spot we see in the sky, “our laboratory measurements clearly agreed with predictions from computer simulations and mathematical calculations, proving that electrons surfing two thousandth waves can accelerate electrons (up to 45 million speeds). MPH) that cause auroras,” Howes said.

“These experiments allow us to make key measurements showing that spatial and theoretical measurements do indeed explain a key method for creating the aurora,” said study co-author Craig Klitzing.

The aurora borealis seen from the International Space Station.

Space scientists across the country were delighted to hear the news. “I was so excited! It is very rare to see a lab experiment validating a theory or model related to the space environment.” “The area is too large to easily simulate in the lab.”

Kuhn said he believes the ability to understand the electron acceleration mechanism that causes the aurora borealis will be useful in many studies in the future.

“It helps us better understand space weather! The electron acceleration mechanism verified by this project works elsewhere in the solar system, so it will find many applications in space physics. “It will also be useful for space weather forecasts, which is something that NASA is very interested in,” Cohen said in an email to CNN.

And a long way to go

Now that the theory of luminous aurora creation has been proven, there is still a long way to go to predict the strength of each storm.

The aurora borealis dance across the night sky high in the Arctic Circle.

“Predicting the strength of a given geomagnetic storm, based on observations of the Sun and measurements made by spacecraft between Earth and the Sun, remains an unresolved challenge,” Howes said in an email.

He added, “We’ve made contact with electrons surfing two thousand waves at an altitude of 10,000 miles above the Earth’s surface, and now we have to learn to predict the strength of these two thousand waves using ‘space observations’.”

Correction: An earlier version of this story misidentified the physicists who wrote the study. They are from the University of Iowa.


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