Solar Flares Ignite Vivid Deep‑Red Auroras Over Fairbanks, Alaska

Solar flares spark unusually vivid northern lights across Alaska

On the night of Nov. 11, 2025, a sequence of solar eruptions produced exceptionally bright and colorful aurora borealis visible across Fairbanks, Alaska, and other high-latitude regions. University of Alaska Fairbanks physics professor Mark Conde and other observers reported unusually deep red and towering swaths of light stretching across the night sky.

“It was like seeing the fine wine of the aurora,” Conde said. “Deep red aurora is quite unusual, and they only really occur during extreme events like this.”

The aurora borealis appears when charged particles—mainly electrons and protons—stream toward Earth and interact with atoms and molecules in the upper atmosphere, producing visible light. Recent eruptions on the Sun sent an enhanced stream of charged particles into near-Earth space, increasing the intensity and geographic reach of the displays.

How the particles get in: As the solar wind flows past Earth it generates electric fields and interacts with our planet’s magnetic field. In most cases Earth’s magnetic field deflects many particles, but when the magnetic orientation of the incoming solar wind is favorably aligned (effectively the opposite orientation), it can slip through the protective magnetic bubble and funnel particles down toward the atmosphere.

“It’s almost like a switch,” Conde said. “(The solar wind) can open the switch and let itself in. And that’s kind of what happened last night, when (the cloud of materials from the solar flare) first hit the magnetic field it was extremely favorable to allow the solar wind to penetrate into the near-Earth environment and pump up the magnetosphere and produce the displays that we saw.”

Why red? The striking deep-red color seen in many displays comes from particles interacting at higher altitudes, where excited oxygen atoms emit red light. This red emission is more common during strong space-weather events when low-energy particles are abundant at those altitudes.

Scientists study auroras not only for their beauty but because auroral activity is one manifestation of space weather, which can affect satellites, radio communications, navigation systems and other technologies. Conde said his team has not yet learned of major service outages from this week’s activity, but the solar flares did disrupt data collection on two university spacecraft used to monitor the solar wind. In previous strong events, solar activity has also altered orbits of satellites—affecting Starlink units, for example—and in some cases contributed to early re‑entries.

The same solar activity that enhances auroras can accelerate radiation to levels hazardous to astronauts and sensitive spacecraft electronics. “If there was an astronaut standing on the surface of the Moon last night—outside the magnetic, protective bubble of the Earth—or en route to Mars, they wouldn’t have been killed, I don’t think, by the radiation, but there would have been enough radiation that they would have had significant health risks,” Conde said.

Beyond immediate operational concerns, researchers value the near‑Earth environment as a natural laboratory for studying plasma physics that we cannot reproduce on Earth. “We can look at plasma phenomena occurring in space that we can’t possibly reproduce on Earth because… if you wanted to study those plasma interactions on the ground, you would need a vacuum chamber that would be 100 kilometers in diameter or something,” he said.

Looking up: The auroras from these events may continue to be visible for a short period as the disturbed solar wind and magnetosphere settle. For photographers and skywatchers in high-latitude regions, clear nights offer a chance to see vivid curtains, arcs and red glows—though viewers should always take standard safety precautions when observing at night.

“Plus,” he said, “It’s pretty!”