At about 7:25 a.m., Alasdair Burns, a stargazing guide on Stewart Island (Rakiura), received a text message from a friend: Go out and look at the sky.

“As soon as we got out, we understood what the friend wanted to say,” Burns said.

He saw a giant swirl of blue light amidst the darkness.

“It looked like a giant spiral galaxy, just hanging in the sky and slowly drifting by. That vortex brings a strange feeling,” Burns shared.

Burns took a few photos and recorded the spiral image with his personal phone.

“We quickly knocked on the door and called the neighbors to come out. We sat on the porch and looked up. Everyone was surprised,” Burns said.

Groups of amateur astronomers on social networks heatedly discuss the images and questions about this phenomenon. There are many theories, from UFOs to foreign missiles to commercial light shows.

“Our orbital black hole is where aliens live,” says one astronomer.

Professor Richard Easther, a physicist at the University of Auckland, called the phenomenon “strange but easily explained”. He thinks the reality is a little sillier.

He commented that these special clouds appear when rockets put satellites into orbit.

“When the propellant is pushed back, water and carbon dioxide will form a cloud in sunlight. The shape of the satellite’s orbit and where we are sitting relative to the sun are the factors that create these peculiar clouds. They can be seen from the South Island,” Mr Easther said.

Mr. Easther said the rocket in question was likely the Globalstar launch from SpaceX. This rocket launch was placed into low Earth orbit off the coast of Cape Canaveral in Florida on June 19.

Burns read about a similar phenomenon in 2009. He guessed that the spiral image was likely from a rocket.

In 2009, a Russian rocket launch also created giant blue spirals that could be seen in Norway.

Even knowing that, Burns still couldn’t believe his eyes: “None of us had ever seen anything like that before. It’s breathtaking.”