Bill Carter had been planning his bucket-list winter vacation to Alaska for 30 years, and he couldn't have picked a better time.
The retired chemist from Jesup, Georgia, didn't mind that February temperatures can hover near -40C on the outskirts of Fairbanks, because the night sky offered Carter something special: the aurora borealis.
"Yellows, oranges, greens. There were light bursts that would come from time to time," Carter said. "There were light rays that seemed to come from the ground up, and from the sky down."
The northern lights can be seen on dark, clear nights when charged solar particles strike the upper atmosphere near the North Pole. Because of a predicted peak in a solar cycle, this year and next are expected to offer prime viewing for the elusive phenomenon.
So Alaska's tourism industry is gearing up for thousands of visitors like Carter who are willing to wait outside in freezing weather, often for hours past midnight, in hopes of catching a glimpse of the lights.
Fairbanks, the largest city in Alaska's interior, is well-suited for aurora tourism because it's just at the edge of the "auroral oval", a ring-shaped region that circles the north magnetic pole where auroral activity is most common.
It also has less cloud cover because of its distance from the ocean, and tourists can usually escape the city's light pollution by driving just 17km out. Dixie Burbank got a glimpse of the aurora as a child growing up in Wisconsin, but always wanted to travel to where the lights are more powerful.
"This has been something I've talked about for years, finally making our trek up to Alaska to see the northern lights," said Burbank, who, like Carter, saw the lights during a visit to Alaska this month.
"Because of the solar max, this was the year to do it."
Solar cycles last roughly 10 or 11 years and the "solar max" is the cycle peak, when the sun emits the most energy.
"The heavens just opened up with activity," Burbank added. "It's sheer excitement to see the lights come out."
When the solar cycle hit its low point or solar minimum in 2006, Nasa predicted that the next solar maximum could produce the most activity since the historic solar max of 1958, when the northern lights could be seen as far south as Mexico.
If you compound that with the fact that aurora activity tends to become more common around autumnal and vernal equinoxes, the start of (the northern) spring in March could be quite hectic for Fairbanks.
"Because of the buzz of the aurora blasts we definitely think it's gotten more attention from the media," said Deb Hickok, the president and CEO of the Fairbanks Visitor Bureau and Convention Centre.
Bernie Karl owns one of the most popular resorts in the Fairbanks area to see the lights. He said his Chena Hot Springs resort has been completely booked from the end of December to the end of March and all of the next northern winter.
Todd Salat, a professional Alaska-based photographer who has been chasing the northern lights for 16 years, said he has seen some of the most powerful auroras of his career this year, and has taken some of his best photographs, too.
"The thing just goes crazy and starts ripping across the sky, then all of a sudden you can't believe what you're seeing - ripples of light going from one horizon to the other in a matter of, you know, five or 10 seconds," Salat said. "[It's] just incredible. It makes you feel small because it's big. It's global."
Fairbanks expects to be inundated with tourists, especially from Japan.
Shigeo Mori, who does Japanese marketing for Chena Hot Springs, explained that the Japanese fascination with northern lights stems from a philosophy that contemplates both sides of nature: its destructive power as well as its natural beauty.
"It's more than a phenomenon for the Japanese people," Mori says.
"It's tradition, it's history."