Uploaded October 2024 | Updated September 2026, 3 days ago

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After I missed the big(ger) geomagnetic storm earlier in May of this year, I caught a pretty good one when I drove out to a high plateau in the countryside this October. I've never seen a video of sub-auroral arc structures observed this far south (~29.7 degrees North latitude). This is a ~35 minute sequence of 35 five-second exposures, spaced roughly a minute apart each, capturing a couple of structures propagating westward (left), as shown by oxygen recombination at 630 nm, or red light, generated in the upper ionosphere. The auroral structures probably map to "Bursty Bulk Flow" regions in the Earth's inner magnetotail. The static, white light is light pollution from Comfort, TX. The gradual dimming is because the quarter moon (half-filled moon) is setting behind me, as I am about to pass through the midnight sector of geospace, in Texas. Note that the North star is stationary. Couldn't see very much with the naked eye, but long exposure tells quite the story.