June 25, 2021

The mysterious appearance of the northern lights has been proven

The mystery surrounding what caused the northern lights is speculated, but has not yet been proven.

A team of physicists at Iowa State University has finally demonstrated that “the most brilliant auroras are formed by powerful electromagnetic waves during geomagnetic storms.” Newly released studY.

These phenomena, also known as alpine waves, accelerate electrons towards the Earth, creating particles of light known to us as northern lights.

“This small population of electrons is subject to‘ vibrational acceleration ’by the electric field of the alpine waves, which is like catching a wave and constantly accelerating as it moves with the surfer wave,” said Greg Howes, associate professor at the department. Associate Professor of Physics and Astronomy and Research at the University of Iowa.

The idea of ​​”surfing” electrons in the field of electricity was first introduced in 1946 by the Russian physicist Lev Landau. His theory has now been proven.

Re-creation of Northern Lights

Scientists have been understanding for decades how Aurora is formed, but have now been able to simulate it, for the first time, in a laboratory on a large plasma device (LPD) in UCLA’s basic plasma science facility.

Scientists used a 20-meter-long chamber to recreate the Earth’s magnetic field using powerful magnetic field coils in UCLA’s LPD. Inside the chamber, scientists created a plasma that looked like it was in space near Earth.

“Using a specially designed antenna, we injected alphanumeric waves into the bottom of the machine, which was like swinging a garden hose up and down quickly and watching the wave travel through the hose,” Howes said. As the electrons began to enjoy “surfing” with the waves, they used another special instrument to measure how those electrons received energy from the wave.

Although the experiment did not recreate the colorful glow we see in the sky, “our measurements in the laboratory clearly agreed with the predictions of computer simulations and mathematical calculations.

“These experiments will make important measurements that show that space measurements and theory actually explain an important way in which Aurora was created,” said Craig Kletching, co-author of the study.

Auroral beads found from the International Space Station.

Astronauts across the country were eager to hear the news. “I was so excited! It’s very rare to see a laboratory experiment that confirms a theory or model of the space environment,” said Patrick Cohen, a scientist at NASA’s heliophysics division. “The space in the lab is too big to simulate easily.”

Cohen hopes that understanding the acceleration mechanism for electrons that cause auroras will be helpful for many studies in the future.

“It helps us better understand space weather! The electron acceleration mechanism verified by this program works elsewhere in the solar system, so it will find many applications in space physics. It will also be used in space weather forecasting, something NASA is very interested in,” Cohen told CNN- Said in an email sent to.

Have to go a long way

Now that the theory of how the glowing aurora is formed has been proven, there is still a long way to go in predicting how strong each storm will be.

The tall northern lights in the Arctic Circle dance throughout the night sky.

“Predicting how strong a particular geomagnetic storm will be based on observations of the sun and measurements from spacecraft between the earth and the sun remains an unresolved challenge,” Howes said in an email.

“We have established a connection of electrons that can navigate in alpine waves 10,000 miles from the Earth’s surface, and now we need to learn how to predict the strength of those alpine waves using spacecraft tracking,” he said.