At first, Ronnie Cole thought the bright light in the sky over South Alaska was an airplane.
Mr. Cole, a guide with Alaska Photo Treks, was setting up a portrait with two of his clients in the wee hours of Saturday when he noticed “something strange was going on with the light”.
“It started to create a spiral pattern. It was really small at first,” he said. “Then it moved out of the clouds and the spiral was still there, and it just got bigger in the sky. That’s when I realized it was something else.”
The blue spiral made its way through the green and red hue of the Northern Lights for about three minutes before disappearing over the tree line at Trapper Creek, about 100 miles northwest of Anchorage.
“I spent over 1,000 hours each winter looking at the night sky,” said Mr. Cole. “I see a lot of weird things in the sky, but that was definitely the most unusual thing.”
It wasn’t until 8am when he got home from the tour that Mr. Cole learned what it was on social media. Strange as the swirl seemed, the answer was simple: SpaceX had launched a Falcon 9 rocket in California, and the reflection of the excess fuel released into the atmosphere probably created the dizzying pattern.
Needless to say, at the time of the phenomenon, the rest of Mr. Cole’s tour clients got out of a nearby van to get a better look.
“It was a really surreal experience to see this constantly expanding spiral coming towards us through the sky,” he said. “I didn’t even bother moving my camera, I just hit the shutter.”
Mr Cole was one of many onlookers, both in person and from a distance, to observe the spectacle of a SpaceX rocket crashing into the natural spectacle of the Northern Lights. The missile launched from Vandenberg Space Force Base in California on Friday night, with 51 payloads on board, and seen over Alaska three hours later. A similar spiral was seen over Hawaii in January.
Don Hampton, an associate professor the University of Alaska Fairbanks Geophysical Institutecalled the sighting “unique,” in part because of the specific conditions that made it possible: It was a clear, dark night on the ground, and the rocket fuel or exhaust was released into the aurora’s direct sunlight, spiraling in “a long, sprinkler effect .
“If this had happened in the middle of winter, you probably wouldn’t have seen it because the shadow from the sun would have been much higher,” he said.
Mr Hampton said the rocket probably dumped fuel so high in the atmosphere that ultraviolet light broke it down and scattered the particles around the world. He said contamination from the rocket fuel was not a major concern.
Aurora borealis, the natural color display commonly referred to as northern lights because of their visibility at higher latitudes, occurs when charged particles from the sun collide with charged particles already in the Earth’s magnetic field, releasing energy into the atmosphere that interacts with gas to create the visible glow.
The lights attract tourists like Mr. Cole and Kristen Lange’s group, who first visited Alaska last year with her husband and now owns a home just north of Fairbanks. She doesn’t have to leave her home in Midlothian, Texas, to see an aurora, though. In fact, Mrs. Lange begins her mornings in Texas this time of year by looking at the previous night’s sky through sky-facing cameras perched atop her Alaska home.
The cameras captured a few shooting stars, meteorites and satellites, but when Mrs. Lange viewed the tape on Saturday morning, she saw a bright ball.
“I was like, ‘What the hell is that?'” she said Wednesday. She sped up the time-lapse video as a blue swirl crossed a green sky and consulted a sky map. “This time we caught Falcon 9.”
She said it was “the coolest thing we could catch.”
And it probably won’t be the last time it happens, Mr. Hampton said.
“It’s just a fun spectacle to watch, and as we continue to do more launches, especially some of the bigger ones, people are likely to see them again,” said Mr. Hampton. “It’s pretty well explained. It’s not the aliens landing as far as I know. They may be landing, but that was no indication they were landing.”