The man who ran away to chase the Northern Lights

Thomas Kast drives guests around the fringe of the Arctic Circle in his van for a glimpse of one of the greatest shows on earth.

Aurora borealis puts on a show as seen from near Rovaniemi, Finland, last week. Picture: AFP

Somewhere over our heads the night sky is dancing the light fantastic. I know this because Scandinavia’s social media is glittering with extraordinary pictures of the aurora borealis.

Over in Swedish Lapland the country’s space corporation has just launched its first “aurora-sounding” rocket, scattering clouds of barium that fall gently through the ionosphere in vivid streaks of green and blue.

Here in northern Finland, however, we are in a race against the snow and a little sick with envy. For Thomas Kast this is a standard night’s work. A quarter of a century ago he left his home near Karlsruhe in southwest Germany for an internship as an electrical and mechanical engineer in Oulu, a city near the northern tip of the Baltic Sea.

He fell instantly in love. In 2018 he quit his job designing communications networks for Nokia to become a full-time professional aurora-chaser. He founded a company called Salamapaja (Finnish for “flash-workshop”) and drives guests around the fringe of the Arctic Circle in his van for a glimpse of one of the greatest shows on earth.

Kast reckons he has seen the display nearly 1000 times, though he stopped counting a while back. It never bores him. Every night is different. Sometimes the ice crystals in the winter air create a shimmering halo around the moon.

Once he was out photographing the aurora when it vanished so he began walking back to his car. Then all of a sudden the sky lit up like a floodlight. “It was the corona, the crown of the northern lights, when it’s right on top of you,” he says. “There was no moonlight but it was so bright that the trees were casting shadows on the snow purely from the light of the aurora.

Thomas Kast

“There are some moments that just touch the soul.”

There is solid scientific evidence that the mammalian brain responds strongly to the prospect of unreliable rewards. This makes sound evolutionary sense. If you live by hunting, foraging or scavenging, you can seldom be ­entirely certain where the next meal is coming from and need a degree of intrinsic motivation to go out and get it.

Over the millennia civilisations have become increasingly good at tracing and shaping these patterns to make the world more predictable. Deep down, though, we still instinctively like a bit of chaos. So it goes with Kast. There are, he explains, a lot of things you can forecast about an aurora. About 1.5 million kilometres away from us, at a point where the gravity of the Earth and the Sun cancel each other out to create a perfect equilibrium, NASA has a spacecraft watching solar weather.

Every time the Sun spews a plume of charged particles towards our planet the probe can give between two and four days’ warning. Kast and his fellow aurora hunters have used elaborate technology to predict where the light show is likely to be best, or even how intense it might be.

Yet the northern lights are a fickle mistress. Occasionally the solar spray misses the Earth altogether. Even when it hits, the aurora comes and goes, fading in and out in a matter of minutes. “It’s like chasing a rainbow,” Kast says. Nor are you likely to get the full spectrum of colours familiar from the glossy photographs. A long-exposure camera shot gathers shades of red and purple that the naked eye often cannot see.

Then, as I am about to discover, there is the weather. We head out northeast of Oulu towards Kuusamo along Highway 20. Even a few kilometres away the glare from the city lights reflected back into the night sky by the snow is overwhelming. Slowly, though, it ­recedes. After 10 minutes or so a very faint green glow materialises just above the northern horizon. Kast takes a turning to the southeast, trying to shake off the clouds, pulling over every few minutes to check the weather updates on his phone. We circle back to the south of the city. No dice. Kast shrugs. It is just after 11pm and the cloud cover is settling in. Time to head home.

There will, however, be plenty more opportunities. The Sun’s ­activity is steadily intensifying, building towards a crescendo in 2026. As far south as northern Germany there have been four sightings so far this season, compared with only one in the half-decade before. At precisely 2am that night Kast messages to say the sky is clearing up and the aurora is in all its glory. It will have to blaze on without me; I am already fast asleep.

The Times