Why Now is the Time to Start Hunting Auroras – OZY

It took a string of four sleep-deprived nights watching chartreuse auroras dance above a horse farm in Iceland for the latest northern lights headlines to hit home: We’re heading toward solar maximum, and solar cycle 25 is impressively powerful.

Translation: It’s getting easier and easier to see vibrant displays of the aurora borealis (or its southern counterpart, aurora australis) — and the odds of catching a lime-green light show will increase every year for the next few years.

We can thank space weather for this spike in northern lights activity.

Wind from the sun consistently soars through the cosmos; when it’s powerful enough, the particle-packed gust slams into Earth’s atmosphere. The collision — a meeting of Earth’s atmosphere and billions of charged particles from the sun — sparks those viridescent and violet ribbons I spent three weeks chasing in October 2022, from a horse farm guesthouse in Iceland to the far-flung fjords of west Greenland.

I caught the auroras over half a dozen times on this trip. They danced more dramatically, and for significantly longer, than any I’ve seen in my six years of northern lights chasing. The lights I chase next year, and the year after, could look even grander.

“Like Earth, space weather has different seasons, but it’s on the timescale of the sun, or solar cycle,” says astrophotographer, author and avid aurora hunter Mike Shaw. The sun’s weather cycle is roughly 11 years. At its mildest point, solar minimum, the sun sees fewer storms; solar winds reach Earth less, and we experience lackluster aurora activity.

Our latest slog of solar minimum ended in 2019. Now, we’re onto the new and above-expectations solar cycle 25 (the 25th increment scientists have tracked since the field began monitoring solar cycles in the 1750s). Solar maximum, the stretch of peak activity, will hit around 2025. As my awe-striking nights of sleep deprivation proved, we’re already reaping the rewards.

“The next couple of years in particular will be prime time for viewing the aurora,” says Shaw.

Before we dive into destinations, let’s talk about aurora-hunting logistics. Spotting the lights requires dark skies far from light-polluted cities, minimal clouds, a wide view of the sky, nighttime darkness (critical given high latitudes experience nearly endless sunlight in the summer) and, most importantly, a strong solar storm.

Lights chasers measure the latter via the Kp-index, which estimates geomagnetic activity and runs on a scale of Kp 0 to Kp 9. According to Space Weather Live, my go-to app for aurora monitoring, Kp 0 correlates with little geomagnetic activity (and therefore few, if any, auroras). Kp 9 means get outside now.

Scientists are still in the early stages of monitoring and improving the accuracy of space weather reporting. That means Kp predictions are just that: predictions. My real-time monitoring hack: my iPhone 11 Pro camera. It takes our eyes around 30 minutes to adjust to the dark, but DSLR, mirrorless, and even the latest iPhone cameras are sensitive enough to pick up the green glow of auroras right away. If I see it on my phone, even faintly, I know it’s time to set up my professional cameras, grab my hot cocoa, and wait.

The final aurora-hunting necessity: a polar destination. The aurora reactions spark near Earth’s magnetic poles. The closer you are to them, the better your chances. In the Northern Hemisphere, this includes places like Alaska, Norway, Finland and Iceland. The latter has long been my go-to for its ease of lights chasing. “We have a lot of open spaces with dark skies in Iceland with no light pollution,” says Eyrún Aníta Gylfadóttir, marketing manager at Hotel Rangá, an aurora-centered property in south Iceland with an onsite observatory and professional astronomers.

You can see the aurora australis near the south pole. Antarctica is the most consistent spot for southern lights sightings; of course, getting there for winter’s darkness is near impossible. During strong solar storms, the southern lights may also dance above destinations like Rakiura/ Stewart Island, New Zealand; Tasmania, Australia; and Ushuaia, Argentina.

Northern lights are synonymous with cold and winter, but you don’t have to face the frigid elements — or fly to the polar regions — to see the show. Sun particles smash into Earth’s atmosphere all year — you just can’t see the reaction in the polar regions during warmer months because nonstop daylight, known as the midnight sun, obscures it.

That’s not the case in the U.S.’s northern border states. In places like northern Maine, Michigan, or Minnesota, you can actually admire that aurora glow all year, even in summer, as long as the storm is powerful enough.

Our shift toward solar maximum will make the latter more likely. “The more intense the space weather and the matter that’s ejected from the sun, the greater the likelihood that the aurora will be so intense that it will extend outward over the surface of the Earth toward a more southern latitude,” says Shaw.

In far-northern spots like Iceland, auroras dance overhead; it’s where the particle collisions occur. Lower-latitude locales like Michigan are further away from the aurora reactions. That means the lights dance at a distance, and closer to the horizon. Wide views to the north with minimal obstructions — think vast water bodies like the Great Lakes — are key for catching a lower-latitude show. My favorite: Michigan’s Keweenaw Peninsula, where hundreds of miles of Lake Superior shoreline see nothing but freshwater to the northern horizon.

It’s hard to beat a summer night watching the lights in a sweatshirt and shorts, something I’ve learned during several successful Great Lakes aurora hunts. But the lack of frozen fingers and chattering teeth does come with a catch: sightings are less frequent. They require a bit of patience and luck.

In Iceland, auroras alight when the storm hits a minimum of Kp 2. Lower-latitude viewing requires a more powerful index — at least a Kp 4 or Kp 5 — but Kp isn’t the only, or even the most accurate, indicator for lights activity in lower-latitude regions.

“The one parameter I look to for a relatively near-term likelihood of auroras is Bt, the total value of the solar magnetic field,” says Shaw, who runs the lower 48’s top northern lights conference, the Aurora Summit. “If that’s around 10 or higher, and the Bz [solar-wind direction] component of that goes negative, as they say in Canada, ‘put your pants on.’”