EXITING THE SOLAR WIND STREAM: Earth is exiting a stream of high-speed solar wind that sparked bright Arctic auroras earlier this week. Slackening wind sets the stage for a quiet weekend. Anything is possible, however, because the equinox Russell-McPherron effect can turn even the slightest gust into a good display. Aurora alerts: SMS Text
SHARK'S FIN AURORA: On Sept. 22nd, photographer Karsten Berger of High Level, Alberta, captured a striking auroral shape: a razor-sharp green triangle jutting into the night like the fin of a shark. It may have been the crest of a breaking Kelvin-Helmholtz (K-H) wave:
"The wind was blowing on Earth and in space," says Berger. "It was hard to keep the camera steady, but these structures were quite sharp."
A Kelvin-Helmholtz instability happens when two layers of fluid slide past each other at different speeds. The shear at the boundary makes small ripples, and if the speed difference is strong enough, those ripples grow instead of smoothing out. In auroras, the "fluids" are plasmas set in motion by a geomagnetic storm.
The time sequence photographed by Berger suggests that the wave is breaking or curling into a vortex. Indeed, it might be linked to a newly-discovered phenomenon called a "rolling magnetic carpet." Space physcists Xiaoyan Zhou (UCLA) and Donald Hampton (U Alaska) described it in a June 17, 2025, Geophysical Research Letter. Basically, Kelvin-Helmholtz waves can curl into such tight vortices that the underlying magnetic fields resemble carpet threads.
Or maybe it's just a shark's fin. Have you seen any strange auroral forms? Submit your photos here.
Realtime Aurora Photo Gallery
Free: Spaceweather.com Newsletter
ALIEN RANSOM CHRISTMAS ORNAMENT: You can't buy this on Amazon. The Alien Ransom Christmas Ornament is only available from the Earth to Sky Store. On Sept. 15, 2025, it flew to the stratosphere onboard a cosmic ray research balloon:
You can have it for $129.95. Think of it as Santa's ransom :) Hand-sculpted in the USA, this humorous ornament is intricately detailed, from the alien pilot to Santa's boots. Durable polyresin construction makes it lightweight enough to hang on any tree but sturdy enough to last for many Christmases to come.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Space Weather Photo Gallery
Free: Spaceweather.com Newsletter
Realtime Aurora Photo Gallery
Free: Spaceweather.com Newsletter