New Zealand stargazers were left puzzled and awed by strange, spiralling light formations in the night sky on Sunday night. The sight was most prominent in the South Island around 7.30pm. According to a Daily Mail report, the spiraling plume of gas lit up the sky over Nelson, a city at the tip of New Zealand’s south island, and travelled 750km south to Stewart Island by about 7.30pm on Sunday. Eyewitnesses say that the spiral wasn't stationary, rather, it was drifting northwards.

Alasdair Burns, a stargazing guide said “It looked like an enormous spiral galaxy, just hanging there in the sky, and slowly just drifting across” and added it was “Quite an eerie feeling.”

Burns snapped a few images of the lights on long exposure, capturing the spiral from his phone. “We quickly banged on the doors of all our neighbours to get them out as well. And so there were about five of us, all out on our shared veranda looking up and just kind of, well, freaking out just a little bit.”

The country’s stargazing and amateur astronomy social media groups lit up with people posting photographs and questions about the phenomenon, which was visible from most of the South Island. Theories abounded – from UFOs to foreign rockets to commercial light displays.

“Premonition from our orbital black hole,” said one stargazer. “Aliens at it again,” commented another.

Mapua local Augustine Matthews, 54, ran onto the deck to watch it with her husband.

“It looked like a planet or star. It was just a white dot with a tiny spiral. And within 10 minutes it had traversed half the sky and the spiral had grown three times in size,” she said.

The exact reason however could not be ascertained but some people from the field in Auckland University said it might have been a SpaceX rocket or formations of gases through clouds.