Sometimes rockets have fuel that needs to be jettisoned, said space physicist Don Hampton, a research associate professor at the University of Alaska Fairbanks Geophysical Institute.

“When they do that at high altitudes, that fuel turns into ice,” he said. “And if it happens to be in the sunlight, when you’re in the darkness on the ground, you can see it as a sort of big cloud, and sometimes it’s swirly.”

Hampton said that when the appearance of the swirl was caught in time-lapse on the Geophysical Institute’s all-sky camera and shared widely, “it created a bit of an Internet storm with that spiral”:

Alien invasion? No, it’s science. Experts say the mystery spiral over Alaska skies on Saturday during the northern lights — captured in this time-lapse — was a vapor trail from a SpaceX rocket launch. https://t.co/6G6cf6oHaC pic.twitter.com/IQM39aHmNk

— The Associated Press (@AP) April 17, 2023

Others also shared footage of the incredible swirly sight:

Image: Elizabeth Withnall / Facebook

SpaceX rocket launch created eerie blue spiral in the sky over Hawaii: reports https://t.co/DgESnWnZrP pic.twitter.com/6wXWwqA6mK

— SPACE.com (@SPACEdotcom) January 20, 2023

The New York Post noted photographer Todd Salat from the southeast of Fairbanks, Alaska, capture the unusual phenomenon:

“I had absolutely no idea what it was … I would say this was maybe the most bizarre thing I’ve ever seen in my life.”

One of his shots is in the header image, as well as below:

Image: Todd Salat / AuroraHunter.com

Who would have thought that Elon Musk is capable of something so beautiful?