New Zealand astronomers have spotted a strange spiraling light in the night sky, and many have taken to social media to discuss the mysterious light show.
The spiral formed over the South Island around 7:30 p.m. local time on Sunday and was seen by residents of Queenstown and Motueka, according to the Herald of New Zealand. Eyewitnesses say the spiral was not stationary, but rather drifting north.
Alasdair Burns, stargazing guide and photographer for Twinkle Dark Sky Tours on Stewart Island, told the Guardian“It looked like a huge spiral galaxy, hanging there in the sky, and slowly drifting through it.”
“It looked like a planet or a star,” local Augustine Matthews told the Stuff news site. “It was just a white dot with a tiny spiral. And in 10 minutes it had crossed half the sky and the spiral had tripled in size. It wasn’t flickering or twinkling, and it was moving pretty quickly.”
Many people on social media speculated that the real cause of the spiral could be extraterrestrial in nature.
One commenter joked it was a “premonition of our orbital black hole”, another saying it was “aliens again”.
As always, the truth is a little less exciting than our imagination.
According to Richard Easther, professor of physics at the University of Auckland, the spiral was caused by a sunlit rocket exhaust plume.
“When the propellant is ejected out the back, you have what is essentially water and carbon dioxide – which briefly forms a cloud in space that is illuminated by the sun,” Easther told the Guardian. “The geometry of the satellite’s orbit and also the way we sit in relation to the sun – that combination of things was perfect for producing these completely goofy clouds that were visible from the South Island.”
The rocket in question was likely one of the SpaceX Falcon 9 rockets launching a Globalstar FM15 satellite.
Once the upper stage of the Falcon 9 rocket is freed, it spins and vents the remnants of fuel as it falls back into the atmosphere, creating the characteristic spiral that New Zealanders saw from below. Fuel is vented as it falls to prevent it from exploding closer to the ground, which could cause debris to rain down on populated areas.
The New Plymouth Astronomical Society posted on Facebook that “SpaceX’s Globalstar 2 FM15 was likely to have passed New Zealand by this time.”
Similar patterns have been seen in the sky in the past at different locations, such as the one spotted earlier this year in Hawaii and Oklahoma, and East Africa in 2018. All of these phenomena have also been shown to be caused by SpaceX launches.