Globes orange light were seen floating over the Lake Rotoroa area in Hamilton on Thursday evening, making two Hamilton residents wonder if UFOs do really exist.
David Perfect wandered outside about 9.15pm on the clear, still evening, and two round balls of bright orange light caught his attention.
A local astronomer said they may have been Chinese lanterns, like those recently released in Te Awamutu.
But whatever they were, their appearance was surreal for Mr Perfect, who had never seen anything like it before.
The fingernail-sized lights appeared to move towards him ''really high up in the atmosphere,'' following the same path.
They were sharing the sky with aeroplanes, identifiable due to their flashing lights and engine noise, but no sound came from the mysterious balls of light.
''Either they were just so incredibly high up or... who knows?''
Mr Perfect ran inside to get his daughter, Cheyenne, and the pair spent five to seven minutes watching the sky-high lights complete an arc, head off at speed, and disappear.
''It was amazing. It was just absolutely incredible. We were just blown away,'' said Mr Perfect.
''We were making a lot of noise - I'm surprised nobody [else] actually came out.''
President of the Hamilton Astronomical Society Dave Owen said it sounded like Mr Perfect and his daughter may have been watching sky or Chinese lanterns, but it was impossible to be sure without having seen it.
Mr Owen said the lanterns were increasingly popular, and described them as deceptive.
''They can appear to go against the prevailing wind. With any object in the sky at night, it's always really difficult - in fact, it's just about impossible- to judge the size and speed and distance accurately.''
So, lanterns are behind a number of reported UFO sightings.
In terms of air traffic, Hamilton International Airport's controllers are not in the control tower after 8.50pm, and were unable to be specific about what was flying at the time of the sighting.