Canterbury 'meteor' may have actually been a plane

The "meteor" spotted above the South Island on Monday night may have actually been a flight full of Australians.

Canterbury residents reported seeing the alleged meteor just after 6pm on Monday night - the exact time a Qantas flight was passing over the area on its way to Sydney from Santiago.

The Boeing 747 crossed New Zealand's east coast above Rangiora at 5:54pm and passed over the West Coast just south of Hokitika at 6:07pm, flying at a height of 12 kilometres. An aircraft at this height would most likely leave a contrail behind it - however, Qantas doubts its aircraft is responsible.

The organisation that controls our airspace, Airways New Zealand, said none of their control towers reported seeing a meteor and none were reported to Airways by pilots within New Zealand airspace.

One witness told Stuff the object was moving "slowly" - this would be more in line with the speed of an aircraft rather than a meteor. Video sent to Newshub also shows the object moving slowly.

But Qantas says the mysterious occurrence wasn't created by one of their aircraft.

"The contrail pictured does not look like it was produced by an aircraft, and passenger jets do not fly at speeds fast enough to create a sonic boom," a spokesperson told Newshub. "That would strongly indicate it's not a Qantas flight."

Contrails are frequently mistaken for meteors, especially when they're lit by the setting sun and appear to have an orange hue like the mysterious Canterbury phenomenon.

An aircraft flying at that height could have been heard, however it wouldn't have caused the sonic boom residents described hearing.

Josh Kirkley from Auckland's Stardome Observatory says they often receive reports of meteors as the sun sets on the contrails created by flights to Australia

"It is extremely likely this was indeed a contrail lit up during sunset," he told Newshub.

MetService meteorologist Ross Marsden agrees that the unexplained sight was most likely the remnants of an Australia-bound aircraft.

"If the air at cruise altitude is cold enough there will be a contrail, and if the air is humid enough the ice cannot evaporate and it can't dissipate," he says.

So what is a contrail?

Despite some theories that they're created by the Government to secretly poison the world's population, much like that trail of thought, they are in fact just a load of hot air.

Just like when you breathe out on a cold day, an aircraft's engine is pumping out hot air into the colder temperatures that exist at altitude. This creates the cloudlike lines of disturbed air that can linger in the sky for hours.