The mystery behind the greatest light show on Earth, the aurora borealis, or northern lights, has speculated but never proven until now and, for the first time, scientists have been able to simulate it in a lab.
What causes Earth’s magnificent northern lights, the aurora borealis, has long been speculated. For decades, scientists understood how the phenomenon was likely created, but they had no definitive proof.
Now, group of physicists from Iowa State University have released a new study proving how the phenomenon occurs. The physicists wrote the “most brilliant auroras are produced by powerful electromagnetic waves during geomagnetic storms.”
According to the study, the phenomena which produces the light show we call the northern lights is due to Alfven waves, which accelerates electrons toward Earth and gives us the dazzling display.
“Measurements revealed this small population of electrons undergoes ‘resonant acceleration’ by the Alfven wave’s electric field, similar to a surfer catching a wave and being continually accelerated as the surfer moves along with the wave,” said Greg Howes, co-author of the study and associate professor in the Department of Physics and Astronomy at the University of Iowa.
The study has also definitively proven a 1946 theory introduced by Russian physicist Lev Landau, who first proposed the idea of electrons “surfing” on the electric field, CNN reported.
With an understanding of how the aurora borealis works, the next step for physicists was to attempt to simulate it in the lab. At the Large Plasma Device (LPD) in UCLA’s Basic Plasma Science Facility, scientists were able to re-create the phenomena for the first time. They used a 20-meter long chamber to recreate Earth’s magnetic field using the powerful magnetic field coils on UCLA’s LPD. Scientists then generated a plasma similar to what exists in space near the Earth inside the chamber. They then measured how the electrons were gaining energy from the wave using another specialized instrument.
“Our measurements in the laboratory clearly agreed with predictions from computer simulations and mathematical calculations, proving that electrons surfing on Alfven waves can accelerate the electrons (up to speeds of 45 million mph) that cause the aurora,” Howes wrote.
Another co-author of the study, Craig Kletzing, wrote: “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.”