"This is the First Officer speaking. We've spotted a glow of light on the horizon."
This is not, ordinarily, what you want to hear on board an aeroplane. Any glowing light should not be worthy of an announcement over the PA system. It should be expected. Or it shouldn't be there at all.
But this isn't an ordinary flight. The plane is a Qantas 787 Dreamliner, an aircraft you so rarely get to step onto in these days of international travel bans. For three hours now, the 787's nose has been pointed almost due south as we blast our way through the dark night sky, ever further towards Antarctica, past New Zealand far out to the left, past Tasmania to the right, on and on over the cold Southern Ocean.
And then, finally, there's light on the horizon. The First Officer makes the announcement and there's a murmur of excitement in the cabin. We can't see anything right now, just darkness from out of the 787's big windows, but something is coming.
The Aurora Australis. The Southern Lights. The lesser-known sibling of the famed Aurora Borealis, the Australis is an equally spectacular natural light display that's just a little trickier to see in its full glory, given the lack of land in the southern hemisphere's high-latitude reaches.
The only way to truly appreciate the Australis's green-tinged grandeur, therefore, is to fly into the auroral zone, which is at its peak on the outer edges of the Antarctic circle. It's here that solar winds from outer space cause disturbances in the Earth's magnetosphere, altering – work with me here – the trajectory of changed particles found in the upper atmosphere, causing them to emit light.
What all of that means is that the sky in this area is usually lit up with an almost supernatural show, and the only way to properly appreciate it is to fly right underneath it, to chase it, to soar under it, to spend hours entranced by its metallic glow.
Video: The Southern Lights seen from a Qantas Dreamliner
This flight is a charter, an expedition run by the team from Chimu Adventures, who are usually more at home ferrying passengers even farther south to Antarctica aboard seaborne vessels. That's not an option right now, of course, so instead they're taking to the skies in a first for Australia, giving passengers a unique vision of an incredible phenomenon.
This feels like a proper expedition too, complete with expert guidance on board. There's David Finlay, a professional "astro photographer" here to help passengers get those perfect shots. There's Dr Grahame Rosolen, a research scientist from the CSIRO, helping plot our course. And Dr Nicholas Tothill, the flight's lead astronomer, an astrophysicist from the University of Western Sydney.
Radio personality Adam Spencer is interviewing Dr Tothill over the PA at one point: "I consider myself a pretty big nerd," he says. "But I'm in the presence of some even bigger nerds here tonight."
And on we all plough into the night sky, hopeful but unsure. Until there it is.
There's a thing you need to know about aurora viewing. As a traveller, there are some destinations you will visit and look at your photos afterwards and be disappointed that your shots could never do somewhere so beautiful justice. Auroras, however, are the opposite. Your eyes can't do justice to what your camera can capture.
I stare out of my window in awe of what is appearing on the tip of the plane's wing: vast sheets of light, apparitions in the night sky, wavy and beautiful. Soon there's a shimmering band of bright light. Later there's a curtain that bends and curls. It's fascinating to watch the aurora as it changes before your eyes, as it appears and disappears, as it swirls and transforms.
However, to my naked eye at least, it's white. It's only when you snap the shutter of your camera, when you give it a nice long, two-second exposure and then check the display, that the full glory of the Aurora Australis reveals itself. It's green, almost neon. There are hints of metallic red and blue. It's an amazing spectacle that the naked eye just can't properly appreciate.
Fortunately, on a flight such as this you get hours to nail the perfect photograph. We're in the auroral zone for a good four hours or so, which means that even with a seat swap halfway through – those seated in the aisles move to the windows, and vice versa – there's ample time to see the lights, as the plane banks left and right, giving both sides of the aircraft a perfect view.
This is bucket-list stuff for so many on board. It's unique. It's amazing. To be honest I'd be happy just to be flying again, to be sitting in a 787 watching a movie, drinking a glass of wine and enjoying the experience of cruising through the sky. But then you add in the Aurora Australis and you have something else entirely.
Eventually, the glowing light around us will fade to the horizon once again as we make our way back to Sydney. Lens caps will be replaced on cameras. People will recline for a short sleep. This experience, however, will take a long time to fade.
The writer travelled as a guest of Chimu Adventures
Chimu Adventures is running four Southern Lights Night Flights in 2022, beginning in April. Fares start from $1295 for economy (limited view) seats, and go up to $7695 for premium business class. See chimuadventures.com