When aurora turns red like this, you’re looking at oxygen glowing more than 120 miles above Earth. During the geomagnetic storm on November 11, the high-altitude reds were the strongest I’ve ever seen. These upper-atmosphere emissions occur far above the more common green bands, and they require particularly energetic solar activity to become visible.

I wrote a deeper explanation of what causes the different auroral colors here: https://www.lwpetersen.com/science-and-nature/what-causes-the-aurora/

#aurora #auroraborealis #alaska