The Northern Lights, Aurora Borealis, is caused by charged particles from the sun striking the Earth's magnetosphere. The particles interact with the gases in our upper atmosphere, making them glow. Oxygen glows green, nitrogen a reddish pink. Aurorae are most pronounced at 55° to 65° North and South latitudes, day or night. Because the aurora is as faint as starlight, it is washed out by daylight and the light from cities and towns. When there is a particularly active storm on the sun (sun spots), the aurora expands and can be seen in Canada and the Northern United States. This expansion follows the cycle of the sun storms. The lights extend further away from the poles when the storm is more active. Sometimes with a very large storm, the Northern Lights can be seen in Florida!
The Northern Lights are visible perhaps two or three times a year in Maine, usually during the winter months. First, be aware of reports in the news about sun spots. Sun sports can disrupt television and radio signals as well as satellite communications. For this reason, unusual sun spot activity is national news. Information on sun spot activity can be accessed on the Internet as well. On a clear night, go somewhere far away from the light of cities and towns, turn off the lights of your car, and wait for your eyes to adjust to the dark (about twenty minutes). Towards the north you will see a green glow. Depending on the conditions, the aurora may appear as just a dull green cloud, or you may see it flicker like flames. Vertical shafts of lights called "pillars" may be visible. Other forms include ribbons and curtains of fluctuating light.
In order to photograph the Northern Lights, you will need a 35mm single lens reflex camera, a sturdy tripod, and a shutter release cable. Set the camera to the B or T setting on the shutter speed dial. This will allow you to lock open the camera with the shutter release cable to make a time lapse photo. You will want to take several photos of varying lengths, between five to sixty seconds, depending on the speed film you use, and f-stop you set the lens for—100 or 200 speed film will work well for such photos. These photographs were taken by Mark Savary using as 28 mm lens @f 2.5. The exposure was approximately twenty seconds on Fuji HG 200 speed film.
This is a view of the aurora looking NNW over Presque Isle. A ribbon-like structure is clearly visible at the bottom of the aurora, as well as the beginnings of several pillars. To the left, over the lights of the town is the moon. Note the comet Hale-Bopp just right of center. Due to a distortion effect caused by the wide angle lens, the lights of the town are slightly smeared at the edges of the photograph. Photo by Mark Savary.
The Northern Lights, looking NNE from Presque Isle. The arc-like shape of this aurora is caused by the curvature of the band of light as it extends around the northern hemisphere. Pillars within the aurora are visible in this photograph. Photo by Mark Savary.
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