Amateur astronomer captures rare double aurora

Photographer Alan Dyer, who is fond of astronomy, captured on camera a strange combination of red and green auroras. He made the video right in the backyard of his house in the small town of Strathmore, in southwestern Canada.

Seeing these lights in the sky, Alan immediately realized that this was something unusual, and began to shoot. At that time, he had no idea that his recording would become the most complete and illustrative video of this rare phenomenon.

Physicists, who themselves have never seen anything like it before, used these frames to understand how such an unusual light show is formed.

The pulsating green aurora in Dyer's video is well-studied: it appears when the planet's magnetosphere interacts with charged particles in the solar wind. But the fruity purple stripe is more mysterious: although scientists knew about these "stable red arcs auroras" for decades, there is no generally accepted evidence for how they form. exists.

One popular theory is that part of the Earth's magnetic field can heat up the atmosphere and, like proton rain, push particles together. But until now, researchers have never seen red and green auroras at the same time, said Toshi Nishimura, a space physicist at Boston University.

Along with satellite observations, Dyer's videos and similar footage taken by other amateur astronomers in Canada and Finland show that the two phenomena are related.

A preliminary theory is that the thin beams in the red aurora show the paths of electrons falling along the Earth's magnetic field. Just as proton rain causes green aurora, electron rain appears to cause red, and solar wind powers both at the same time. Because electrons carry less energy than protons, they are more reddish in color.

But raining electrons might not be the only way to cause this red glow, warns Brian Harding, space physicist at the University of California at Berkeley. Understanding the causes of the red aurora could help scientists predict space weather like normal weather, he says. But it's too early to talk about it. More research data is needed.