They came by the dozens, from as far away as Hawaii and New York City. They gathered on the shores of a rocky beach on the North Shore, staring hopefully at the night sky on a raw November weekend. They were searching for the light, for an addictive, unearthly glow, a source of inspiration, awe and envy-inducing Instagram photos. This is what happens when you hold a conference of Aurora Borealis chasers in Minnesota.

The Aurora Summit, now in its second year, bills itself as the leading conference in the U.S. for fans of the eerie, elusive night sky phenomenon also known as the Northern Lights. Held last month at the Superior Shores Resort in Two Harbors, the three-day meeting attracted more than 100 scientists, folklorists, authors, photographers, dark sky advocates, artists and others in thrall with the Aurora Borealis. The conference is an outgrowth of gatherings of Aurora Borealis chasers at Two Harbors that have been going on for years.

Here's the scientific explanation for the Northern Lights: Sunspots and storms on the surface of the sun throw off tremendous amounts of electron and ion particles. After traveling through 93 million miles of space, those particles collide with and excite molecules in Earth's atmosphere, releasing light that can be seen in the night sky, most typically in the far northern parts of the world. But it's much more than that, according to devotees of the Northern Lights.

A connection with the world

The shimmering waves, glowing pillars, or writhing snakes of green, red or violet light seen in an Aurora Borealis display can cause coyotes to howl and loons to scream and inspire a powerful attraction for some humans.

"It's a sheer thrill to see it," says conference organizer Melissa Kaelin, an author formerly from Eagan. "When you see it and it expands and rises above you, it really inspires a feeling of awe and connectedness and inspiration."

Mike Shaw, another conference organizer, says a really strong Northern Lights display is "mesmerizing." He says the emotional response is "joy." "It's as if you're under a glass salad bowl and someone is pouring light over it," says the St. Paul photographer, author and former physics and astronomy professor. "You feel this connection with the world you live in and it's reassuring."

One conference attendee describes the lights as "green crack," an addictive vision that compels Aurora Borealis chasers to travel to remote corners of Alaska, Iceland and Greenland at inhospitable times of the year for a chance at a Northern Lights fix.

Aurora Borealis chasers say the lights typically are seen around midnight or later, meaning that dedicated hunters often spend a lot of time standing alone, outside in the middle of the night in the pitch black back of beyond, staring at the sky. No wonder that during one panel discussion, Kaelin asked participants to share an Aurora hunting experience that made them want to run for their lives. Getting spooked by things that go bump in the night is part of the hazards of the chase.

"Some people have gotten really freaked out by a beaver flapping its tail in the woods," Kaelin says.

For many, another big part of the experience is capturing the light show on camera. "It's something you want to share. It's something a lot of people don't get to see," says Carl Jacobsen, who came from Green Bay, Wis.

The conference featured lots of discussion of lenses and tripods and exposure times and tips on how to keep camera batteries from freezing in the cold. One idea: Try wrapping the camera housing in a turkey roasting bag with some chemical hand warmers. "Don't start," growls one participant when a well-worn Canon vs. Nikon debate threatened to flare up.

One of the conference sessions was devoted to developing a social media following for Aurora Borealis photos. Another was devoted to a recently identified, mysterious relative of the Aurora Borealis, a narrow arc of colored light known as STEVE. Some of the conference attendees had seen the Aurora Borealis dozens of times. Some were hoping to get tips on how to see it for the first time.

Pamela Dyl, 23, says she's witnessed the light display at least 100 times, ranging from her backyard in Calumet, Mich., to a recent Aurora Borealis hunting trip to Alaska. "I've learned to be patient," she says.

An elusive challenge

An Aurora Borealis sighting might be compared to experiencing a solar eclipse. Except that a total solar eclipse, though much rarer than the Aurora Borealis, is completely predictable. Caused by the clockwork movements of the moon, sun and Earth, we know exactly when, where and how long an eclipse will occur. The Aurora Borealis is generated by solar winds and storms, sunspots and coronal holes. Those are tracked by the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center, but the predictions can be iffier than weather forecasts.

Devoted Aurora Borealis chasers regularly consult online reports measuring solar wind speeds and density. They check live cams displaying sky conditions in other parts of the world. They download apps that will give them alerts when conditions are favorable for a sighting. At the conference, they talked of jumping out of their cars, rushing to set up their tripods in the dark to try to capture a light display that could disappear without warning.

"You have to enjoy going out in the dark, late at night, usually when it's very cold, with a moderately poor chance of success. If you don't like that sort of thing, you're not going to enjoy chasing the lights," says Bob "Astro Bob" King, an amateur astronomer and photo editor at the Duluth News Tribune. "It's more elusive," says Cheryl Mandelbaum, a New York City woman who came with her husband, Marc, to try to glimpse a sight of the Aurora Borealis in Minnesota. "That's part of the appeal. When you find it, wow," Marc Mandelbaum says.

Michael Jordan, a Zimbabwe native who now lives in Duluth and works for Microsoft, says he's come up with his own formula of analyzing solar winds to accurately predict Northern Lights displays. Jordan says he's scheduled plane flights to Europe, getting window seats on the left side of the plane so that he can take pictures of the Aurora Borealis midflight. He uses a black shroud with suction cups to eliminate reflections on the plane window. "I've had people calling the air steward wondering if I was planting a bomb," he says.

Jordan says thanks to a quirk in the magnetic field that results in something called the "Auroral bulge," Minnesota is particularly well-positioned to see the Northern Lights. It can be seen farther south here than in other parts of the country, he says. "If that didn't exist, we wouldn't be Aurora hunters. We'd be tornado hunters," Jordan says.

But the Auroral bulge didn't appear to help much during the conference.

Despite standing watch on the beach late into the night and waking up in the predawn hours to check the space weather conditions, the Northern Lights watchers didn't see a glimmer of the elusive Aurora over the two nights of the meeting. On the morning that the conference was ending, Kaelin consults an NOAA space weather website on her phone. A map shows a glowing green cap of solar winds bathing the top of the world, dipping down into Minnesota.

"Thirty-two gigawatts of hemispheric power," she says to Shaw. "Mike, if it were dark right now, we'd be seeing that." Shaw responds with a long sigh.

Kaelin says some attendees planned to stay an extra day. Perhaps they might see it that night. "She's an elusive creature," Kaelin says of the Aurora Borealis. She says the Aurora is camera-shy, but willing to reward especially devoted followers. "I like to believe the Aurora comes out on special occasions for special people," she says.