Science
Eye on the Sky
Dr John Mason’s passion for the northern lights stretches back decades. His modern-day mission, however, is to share his insights about Arctic skies.
WORDS JOHN BURFITT
The northern lights is a topic that can keep British physicist and astronomer Dr John Mason talking for hours. More formally known as the aurora borealis, their spectacular appearance in Arctic skies has kept the acclaimed scientist busy for decades.
But for all the many words he uses to describe viewing the phenomenon, there’s one significant word he keeps coming back to: patience.
© Dr John W. Mason
“Patience is the key thing when people travel to see the northern lights,” Dr Mason says. “Nature does not necessarily run to our timeline, but when the lights do appear, they are often worth every moment of the wait.”
August 5 1972 is the milestone day when Dr Mason, at the time aged 18, first fell under the spell of the northern lights during a rare auroral display over southern England. “And I have been fascinated by them ever since – it’s addictive, almost like a drug,” he says, laughing. “No matter how fantastic they’ve been, you always want to see more as you never know if the next display will be even better.”
“No matter how fantastic they’ve been, you always want to see more as you never know if the next one will be even better.”
— Dr John Mason
© Dr John W. Mason
The skies above
Dr Mason, 67, lives in West Sussex in the UK, and has been making regular visits to the Arctic region over the past 30 years to witness the northern lights. Every year since 2008, he’s travelled with Hurtigruten on voyages along the Norwegian coast, acting as a guide and sharing his expertise about what’s going on in the skies above. As passengers crane their necks skywards, there’s one question Dr Mason is always asked: what exactly are the northern lights? “I never get tired of answering that as I want people to understand just how amazing what we are seeing really is.” The aurora borealis is caused when electrically charged particles that originate from the Sun’s outer atmosphere are funnelled into Earth’s atmosphere around the north magnetic pole in a region known as the auroral oval.
Photos © Dr John W. Mason
As the particles collide with atoms and molecules of oxygen and nitrogen in the upper atmosphere, they excite them to produce light. The most common auroral colour is a pale green, between 100 and about 150 kilometres above the ground. Above 150 kilometres, there’s a faint red light, while sometimes, in twilight, a purplish colour may be seen, as can turquoise, violet, lilac and deep red. “When you first see an auroral display, it might appear to the eye as a greyish tone, but that will slowly change and form an arc of greenish light – sometimes with rays a bit like searchlight beams extending upwards from the arc,” Dr Mason explains. “This phenomenon then presents a huge variety of forms that may develop into something amazing and can change within a matter of minutes.”
© Dr John W. Mason
Best of the season
In the Arctic, the northern lights season runs from the end of September to the beginning of April, as the dark skies offer the best visibility. “You only see the colour when the light level is high enough to trigger the colour sensors in your own retina,” Dr Mason explains. The best viewing place is within the auroral oval, which usually lies to the north of the Norwegian city of Tromsø, but they are often visible further south. The type of display one sees depends on where a person is in relation to the auroral oval. “The activity of the display also depends on the type of electrically charged particles entering the atmosphere, how energetic they are and how many collisions occur in a given time,” Dr Mason explains. “Major eruptions from the sun can also lead to a greater influx of particles causing the auroral oval to intensify and become more active.” The changes in Arctic climate in recent decades have had no impact on the vibrancy of the northern lights, due to their high altitude. “The changes I have witnessed are in the weather and climate of the Arctic, which is now generally rather milder and is not as stable,” Dr Mason says. “Over the longer term, there will be changes in Earth’s magnetic field, and that will ultimately affect the aurora.”
© Dr John W. Mason
A bridge to the heavens
Accounts of auroral displays date back more than 3,000 years, when ancient civilisations were so awed by the spectacle of the rays of light across the sky that a range of legends were created. One of the most popular claimed the aurora was a bridge between heaven and earth, and the rays were the souls of the dead on their way to heaven. In other accounts, Vikings believed the lights were reflections from the shields and armour of the Valkyrie.
“It’s amazing what you can see,” Dr Mason says. “A few years ago, I saw a display that looked like a dragon and the hairs on the back of my neck stood up. Once they begin to evolve, the lights take on a character all their own, which makes them as fascinating today as the first time I laid eyes on them.”
© Dr John W. Mason
Forward to the future
For the time being, Dr Mason, who was awarded an MBE (Member of the Order of the British Empire) in 2009, is keeping his eyes firmly fixed on the coming northern hemisphere autumn. That’s when he hopes to return to Norway on the next Hurtigruten voyage after the impending lifting of restrictions. “It’s always the most amazing adventure and sharing it with other people adds to that,” he says. “As we look into the skies to see the Northern lights, I always think how lucky we are to see this.”