Aurora borealis
Northern Lights are magical.
For those of us who live in the northern latitudes, these magnificent light displays, the aurora borealis, remind us of the indescribable beauty of nature. Nothing man-made or artificially generated even comes close. It’s as if the heavens open and the colorful light penetrates down and pulses and dances across the horizon. It makes you feel small and insignificant but also mesmerized by the intense beauty falling from the sky.
The cosmic definition of an aurora is the result of disturbances in the magnetosphere caused by the solar wind. These disturbances alter the trajectories of charged particles, which consequently precipitate into the upper atmosphere. The particles get excited and dance and, coupled with the surrounding atmosphere, emit light of varying bands and colors.
The Northern Lights are most clearly seen against a dark sky, generally after midnight. Magnetic Midnight is a term coined by astronomers that occurs when the pole is exactly between the sun and an observer on Earth's surface. At that moment, the pole's aurora reaches its largest extent.
Auroras seem to be more frequent and brighter during the intense phase of the solar cycle when coronal mass ejections increase the intensity of the solar wind. Geomagnetic storms that ignite auroras may occur more often during the months around the equinoxes. It is not well understood, but geomagnetic storms seem to vary with Earth's seasons.
There are also Southern Lights, or aurora australis. The words borealis and australis are derived from the names of the ancient gods of the north wind (Boreas) and the south wind (Auster) in Greek mythology.
In the Upper Peninsula of Michigan, typically the best Northern Lights viewing is on the shores of Lake Superior with a broad view of the horizon. But sometimes especially strong geomagnetic storms can expand the range of the aurora borealis. It’s a rare occurrence, but right around the fall equinox in 2023, we were treated to the lights over Otter Lake (photo below). What a show!
Northern Lights over Otter Lake, Sept. 19, 2023.
Photos courtesy: George Bailey (Eagle Harbor, Mich.), art by Kristine Cooper, @jakeheitman (Hallow Rock, north shore of MN), Travel Keweenaw (Hancock, Mich.), Kevin Roddy (Otter Lake; Tapiola, Mich.).