PINEDALE – As most were tucking into bed for the night last Saturday, something special and seemingly rare for this part of the country was taking place high in the evening sky.

As the sun began to set behind the Wyoming Range, local photographer Dave Bell decided to take advantage of the optimal weather and clear skies to shoot a 30-minute-exposure photograph highlighting the North Star, also known as Polaris. After heading indoors to process his photograph, he took another look outside and noticed something unusual.

“I saw the glow and thought, ‘Wow, that’s weird,’” Bell said. “I headed down to the dock on the lake. It was so bright; it was unbelievable.”

It was approximately 11:30 p.m. when Bell snatched his camera and ran back outside. The bright band of light that hovered above the Wind River Range to the north was, in fact, what Bell first thought. He was in the midst of witnessing the aurora borealis – also known as the Northern Lights – come to life before his very eyes.

“It seemed to get bright the longer it went,” he said. “It never faded a lot.”

After a long day of photographing a local calf branding, Bell stayed up until 1:30 a.m. capturing the natural phenomenon through the lens of his camera.

Aurora storms can be quite elusive this far south in Wyoming, and typically are strong enough to be seen a handful of times a year. According to NOAA Space Weather Prediction Testbed Director Rodney Viereck, the sun goes through an 11-year solar cycle. The current cycle is the 24^th recorded cycle since recording began in 1755. The current cycle began in 2004. Of each 11-year cycle, northern Wyoming gets to witness the aurora between 50-75 times, Viereck said.

The aurora borealis is caused by activity on the surface of the sun, 93 million miles away, according to earthsky.org. Massive storms on the sun send charged solar particles into space. When Earth is in the path of these particle streams, the planet’s magnetic field and atmosphere react, causing the aurora borealis to dance across the sky.

The aurora can appear in a wide variety of ways, from arcs to spirals, and in a wide range of colors.

The lights are quite common in the far northern reaches of the northern hemisphere, including Canada, Greenland, Russia, Alaska and Iceland, to name a few. When strong storms arise, northern states such as Montana, Oregon, Washington, North Dakota and others can frequently catch a glimpse of the natural wonder. If the storm is strong enough, areas such as Wyoming can get in on the scenic wonder.

Solar storms are rated on a scale of G1 to G5. Saturday’s storm was a G3, and Viereck said in the grand scheme of things, the aurora display was “not that strong.”

“During a normal 11-year solar cycle, we can see about 200 such events, but this last solar cycle was smaller than normal so we did not see as many storms,” he said.

In terms of how strong a storm has to be for areas further south to witness aurora activity, storms are rated on a Kp, or Planetary K Index that runs from 0-9. Saturday’s display featured a Kp between 7 and 7.65. Storms need to be around a 7 Kp to be seen in Sublette County.

“Kp indicates what the global geomagnetic storm conditions are and your local conditions are indicated by the local K value,” Viereck said. “Kp = 7 is not terribly high. It is a quasi-logarithmic scale, so Kp = 8 is about 10 times a Kp of 7 and Kp = 9 is about 10 times bigger than a Kp = 8.”

As for future storms that can be seen from Pinedale, Viereck says we are entering the minimum of the 11-year solar cycle, which will last a few years.

“We will probably get two to four storms of this magnitude per year, even at solar minimum,” he said. “This has been a lackluster solar cycle and the geomagnetic storms reflect that.”

The Northern Lights can emerge with little-to-no warning, and can vary in terms of activity, changing within mere seconds in the night sky. Saturday’s storm started out strong, with a ribbon of purple and green skittering from east to west, which lasted around 30 minutes before a large vertical column, called a “Steve” lit up the sky. From the naked eye, the column appeared as a bright white object in the sky. By using exposures of 30 seconds with a camera, the white object was actually made up of vivid purple and green hues. The “Steve” lasted around 30 minutes before slowly dissolving into thin air around midnight. To the north, a vivid band of green and purple pulsed well into the night.

“This was a fairly average storm,” Viereck said. “We have seen a few of these in recent years, even though we are entering the solar minimum period.”

The largest storm of the modern era occurred between October and November in 2003. During a period of a few days, the Kp index moved above 9 several times, with states bordering the Gulf of Mexico catching a glimpse of the vivid lights.

The most powerful storm on record took place in September of 1859, known as the Carrington Event, when a solar coronal mass ejection hit Earth’s magnetosphere. Lights from this storm were visible in India, Mexico, Cuba, Hawaii and even as far south as Colombia. The event was so intense that currents on the telegraph wires set fires in telegraph offices, but due to not having modern measurement techniques in place, the true magnitude of the storm is unknown.

So, when out during the evening hours, take a look northward. You never know what might happen. For those who want a better idea of when a strong storm is coming, phone apps like “Aurora” can provide notifications. The Internet has a wide variety of useful websites, such as www.softservenews.com, which can provide useful tips and information to increase the chances of witnessing one of nature’s most unique spectacles.