In the last few months you may have noticed an increase in Northern Lights action, with intense displays. I hope you had a chance to observe the stunning visuals.
There is no equipment required, unless you bring your camera, or maybe a chair to enjoy the show.
What is the Aurora?
The aurora borealis (northern hemisphere) and aurora australis (southern hemisphere) are phenomena that take place in the upper atmosphere between 100-km and 1,000-km elevations.
When you have solar activity, or an explosion on the sun’s surface – also called a Coronal Mass Explosion – massive amounts of energetic particles blast toward Earth at speeds of a million kilometres per hour.
When these solar particles hit Earth’s atmosphere, they are deflected by our planet’s magnetic fields. These particles cruise along magnetic lines and eventually enter the atmosphere over the magnetic poles.
When these particles interact with the gases of the upper atmosphere, they become electrically stimulated. This is what causes the glow.
As for those wonderful colours, the most common is the eerie greenish-white, which is a result of solar particles reacting with oxygen gases.
Under extremely low atmospheric pressure, red colouring and tinting can also be seen. Blue colouring can be attributed to interactions between solar particles and nitrogen gases.
The more active the sun’s surface, the more frequent and more intense the aurora. At sunspot maximum, aurora can be seen as far south as Texas.
The closer you live to the poles, the better chance you have of seeing auroras (more formally, aurorae), and the more intense the display.
Many think that the aurora borealis is most commonly seen in the winter months. Actually, March, April, September and October usually have the most frequent and intense auroral displays.
Our sun has a cycle of solar activity, and the frequency and intensity of the aurora are directly tied to it. Increased solar activity means increased auroral activity.
We are currently at the peak of the 11-year solar activity cycle; consequently, the auroral viewing has been much better.
To power up an auroral display requires an energy input of about 1,000 billion watts of power. Up to one million amperes of current can sail along an aurora during an intense display.
These massive energy currents are so powerful that they create fluctuations in Earth’s magnetic fields. This in turn can kill power networks, telecommunications and satellites, and even disrupt pipelines.
For information as to whether the aurora will be out tonight, here are a few great websites: www.spaceweather.com, www.auroraborealisyukon.com and www.skynews.ca.
Now that we have a better understanding of how the Northern Lights work, let me share with you my most recent adventure.
About three weeks ago, left town and headed toward Saskatoon, a 2,300-km drive. Before we reached Watson Lake we drove into a very thick, low cloud. By the time we were 800 kilometres south of Whitehorse, the fog was so dense we could see only 10 feet ahead of us.
Finally, at the very top of Pink Mountain, B.C., we climbed out of the low cloud and were presented with an inky, blue-black night sky that was nothing short of miraculous.
The sky was full of stars and the Milky Way stretched from horizon to horizon.
And, what is that to the far northern horizon? The beginning of the most intense aurora shows that I have ever seen!
As usual, it started with a greenish glow like a cloud creeping across the horizon. Within a few minutes, bands of brighter aurora were arcing their way across the night sky.
After five minutes, huge pulses of light and energy started to ripple across the already bright green arcs! Sometimes the pulses were short, while others travelled the entire arc all the way to the far horizon.
I sat there fascinated and totally engrossed. I nearly forgot to grab my camera and take a couple of photos.
While setting up the camera gear on the side of the road in the middle of nowhere at 3 a.m., I decided to make a quick sweep of the local surroundings with a flashlight for eyes, to make sure that I was alone.
With everything set up I pointed the camera toward the night skies and chose my field of view. It was hard to concentrate on photography when in the blink of an eye a huge light pulse would zip across the entire length of the sky.
Not only was the aurora bright, it was also widely varied, from great greenish arcs that climbed across the entire sky to softer, darker green clouds. Pillars and spires of intensely brilliant light – seemingly random – lit up everywhere.
I consider myself fortunate to have seen this auroral event, and under such amazingly dark skies. Simply awesome!
So keep looking north in the night sky and keep checking those websites, and you, too, will have an awesome Northern Lights experience.
James “Deep Sky” Cackette can be reached at firstname.lastname@example.org. See his photo adventures on Facebook at Yukon Night Skies.