Here's how you can maybe, possibly see the northern lights near Calgary this weekend

There's a few reasons why astronomy enthusiasts keep tight-lipped about their aurora borealis predictions.

One, saying it's going to happen means it won't (or so the superstition goes). Two, sightings are notoriously hard to predict, requiring a perfect recipe of solar activity to be visible. Three, conditions can change rapidly, and no one wants to overpromise and under deliver.

So let's just say, according to the latest data (seen here and here), this weekend looks encouraging.

"We are coming into a more dense solar wind, and we are in a region of a somewhat faster than normal solar wind speed," said Eric Donovan, professor of physics and astronomy at the University of Calgary.

"That combination … has the likelihood of giving us good aurora on Saturday night, Sunday night and Monday night."

But, no promises.

Green lights have been seen dancing around the city skies recently, with Calgarians posting photos of their sightings on Twitter and prompting questions about when the next shimmering show will take over the night sky.

It's a sight worth seeing, says Alan Dyer, an astronomy writer and photographer, but he agrees, it's illusive.

"The likelihood seems to be better starting Saturday, but will it be the case for us at night here? Or maybe Europe gets the show and we don't," he said.

"For the most part, you got to kind of look at the prospects and head out, take a chance, and if something happens, fine. If it doesn't … that's the fun of aurora chasing."

Aurora Borealis

If you want something to blame for the aurora's undependable nature, look up. The sun's super hot tendrils, also known as the solar atmosphere, determine whether the show goes on. 

"It's so hot that all the particles in the [solar atmosphere] have what we call escape velocity, so they bubble up from the surface of the sun … blowing outwards through space constantly, and we call that the solar wind," said Donovan.

"Solar wind is just this electrically active gas that is flowing outwards through the solar system, everywhere in the solar system, outwards all the time."

That wind meets up with the earth's magnetic field and creates the aurora borealis, or northern lights. 

On clear nights, the aurora is almost always visible in areas near the north and south poles. They're home to twin, ever-present auroral ovals. 

For the lights to be visible in Calgary, a geomagnetic storm is usually required.

"The rate of energy and material being dumped into the magnetosphere, at times, it gets really large. And when it gets really large and sustained for a few days, then the auroral oval tends to expand, get brighter and bigger and also expand so that it's seen at lower latitudes," said Donovan.

Determining just when that material shoots out is the tough part. And even if it does happen, the material can miss the earth's magnetic field completely. 

Or maybe the show is short, or it happens in the middle of the afternoon when it's not visible.

"We never really know," Donovan said.

Setting up for success

Of course, some preparation can help increase the likelihood of a successful sighting.

Donovan says the season does play a small role.

"That has to do with the angle the earth's magnetic field makes with the solar wind direction, which changes systematically over the year. And so geomagnetic activity is more likely near the equinoxes [March and September] than the solstices," he said.

Aurora chaser Christy Turner says she heads out anytime the data looks promising, and sometimes, you don't have to go far.

"I have watched a few shows in the past from Nose Hill [Park], and if you're south of the city, just heading east outside of the city light pollution is great," Turner said in an interview on the Calgary Eyeopener.

"Basically anywhere that you're not obstructed, looking northeast."

Turner is also a NASA citizen scientist, which means she shares photos of the auroras to help scientists make new discoveries. Her photos have been used in scientific journals to present new phenomena.

"I've been paying particularly close attention in the last couple weeks just because of all the activity on the sun," she said.

"If I'm not going to catch any auroras, maybe I'll catch a couple fireballs."

Some of Dyer's photos have also been used in research papers, which he thinks is an additional incentive to get out and snap some pictures.

"We still don't understand what's going [on] up there, and because more and more people are paying attention to the northern lights ... we're just seeing unique, unusual shapes and formations and colours and features that were going unnoticed before."

His best tip is to keep an eye on the Alberta Aurora Chasers Facebook page. Members will post the latest updates on conditions and upload photos of any potential glimpses of light.

"No matter how many times you see the aurora, it's always fascinating to watch just the motion and the colours," he said.

"You have to be patient and head out … Just enjoy the night sky and the stars for what it is. And if you get an aurora, it's a bonus."