Humans use two different kinds of cells in their eyes to sense light. Cone cells, concentrated in the fovea in the central area of vision, are high resolution and detect color in bright light. These are the main cells we use for vision in the daytime. Rod cells, concentrated in the periphery around the outside of the fovea, can detect much fainter light at night, but only see in black and white and shades of gray. [The aurora or northern lights] only appear to us in shades of gray because the light is too faint to be sensed by our color-detecting cone cells.
What are the Northern Lights (Aurora Borealis)?
The northern lights surprise stargazers by appearing in many forms—from patches or scattered clouds, to streamers, arcs, rippling or dancing curtains. The lights move and change shape and color. Scientists attribute their vibrant colors to excited gases emitted in Earth’s atmosphere; oxygen gives off the green color of the aurora.
Short answer? The sun. The lights are caused by the interaction between the Earth’s magnetic field and charged particles from the sun’s atmosphere that enter the earth’s atmosphere. A solar flare (energetic particles from the sun) floats through space on the solar wind, eventually penetrating the Earth’s magnetic field. Electrons in the magnetic field sideswipe oxygen atoms or nitrogen molecules in the Earth’s atmosphere.
The bursts of colorful light—the northern lights—are colliding particles (usually electrons) and atoms; at collision, electrons can return to their initial, lower energy state, and in the process, release photons or light particles we know as aurorae.
Forecasting Northern Lights Sightings
Aurorae happen; there’s no set schedule. Often, auroras happen with just 30-minutes warning; others speculate multiple-day warnings and peg periods around the spring and fall equinoxes for increases in aurora. Kp-index readings (the global geomagnetic activity index) of six plus (6+) indicate the potential to see the northern lights.
Scientists use satellites to measure the speed and density of the solar wind, and when the conditions are right, they can predict when the Northern Lights will occur. The intensity and location of the Northern Lights can also be forecasted using computer models based on real-time data from various instruments.
Just like Earth’s cycles or seasons, the sun’s energy output also fluctuates on a roughly 11-year basis or solar cycle. Scientists refer to the solar cycle like a pendulum, swinging back and forth between periods of highs and lows. Forecasters expected the next solar minimum to arrive in 2019–2020—but not to worry—auroras still appear in the night’s sky. It’s just that “solar maximums,” or peaks in the sun’s activity, likely result in greater frequency of aurorae. According to one source, 2022–2027 may be the best years for aurorae sightings.
Viewing the Northern Lights
It is notoriously hard to predict catching the northern lights—they are a naturally occurring phenomenon after all—and a clear night sky is a must. Maximize your changes of seeing an aurora borealis shower by following these tips no matter your location in the northern hemisphere.
Best Time of Year
Best bet to see those green and pink nightlights? August through April—October, November, and April being peak months. Check out NOAA’s three-day forecast and 30-minute forecast (or download your favorite aurora app), hope for a clear night sky, and dress warmly before heading out.
There is no set time for the northern lights, as solar flare activity can even happen before dark. To increase your chances, watch forecasts after 10 p.m. When you head out, have some patience. The best light shows may be during the most unexpected times. You may need to wait for hours or even several nights to see them. Keep in mind that the northern lights may be visible for only a short time, so it’s important to be ready to capture the moment when they appear.
Best Viewing Locations
We can put this most simply: Find the darkest place you can. Activity starts in the north sky, and depending on strength, can spill overhead into the southern sky. Ideal spot? The south end of a lake or field, free of any man-made light. Dress in warm layers and bring snacks and drinks to stay comfortable while waiting for an aurora borealis shower to appear.
Favorite Local Viewing Spots
There are many great viewing locations that are not too far from Michigan Tech. Anywhere north of Houghton (over the Lift Bridge) ensures more open sky and less light pollution—perfect conditions for aurora sighting. Remember that the darkest spot you can find may be the best. There are also many great viewing locations in the Copper Country:
- Breakers Beach in Houghton (or West Point Entry)
- McLain State Park in Houghton
- Bete Grise Beach, east of Lac La Belle
- Eagle River
- Eagle Harbor
- Copper Harbor’s Brockway Mountain
According to Marquette resident Shawn Malone, the best place south of the Mackinaw Bridge is Headlands International Dark Sky Park. Two miles west of Mackinaw City, this international dark sky park is one of the few dark sky parks in the country.
Once across the bridge, catching aurora borealis anywhere along the south shore of Lake Superior is optimal:
- Brimley
- Whitefish Point
- Pictured Rocks
- Autrain
- Marquette
- Big Bay
- Skanee
Seeing aurora is breathtaking, but what about colors?
While observing the aurora, or northern lights, is a truly awe-inspiring and often breathtaking experience, the images that come out of modern day DSLR cameras may not match what you witness in real life. Especially if you live below about 50 degrees N. latitude, as I do in Unity, Maine.
I’ve photographed many colors in the fantastic northern lights displays. And I’ve been lucky enough to observe many colors: green, purple, yellow, orange, red, magenta and blue. But I never really know what color they are unless I’m looking at my camera’s LCD screen. Or more importantly, viewing these images on my computer.
To my eye, at my latitude, the aurora is typically low on the horizon, and it tends to come in shades of grey. With only a small amount of color, as in the photo above.
Latitude makes a huge difference in aurora
I’ve heard from folks who have visited or lived in areas such as Alaska, Norway or higher northerly latitudes. Where they live, the aurora is usually overhead, not on the horizon. So, the colors of an aurora are easily seen with the unaided eye.
Also, I made the attached graphic (below) to show what I mean. Because these three photographs exemplify the most impressive aurora displays I’ve seen. The skies in the top row of images are de-saturated by color (green, yellow, red, magenta, purple, blue) to show what I saw with my eyes.
A bit of green has been retained on the horizons and just a bit of the color that I remember seeing above that – red, violet, and red respectively.
Camera settings for aurora
I generally set the white balance on my camera at Kelvin 3450 to 3570 when shooting the features of the night sky. But I will also take a few frames with it set on auto to see what colors the camera thinks it should be capturing. Most times I end up going with the Kelvin setting, which is a little bit on the cool/blue side of the spectrum.
The EXIF data for these shots are K-3450, K-3570, K-3570 respectively. I process all my photos through Lightroom 4 & Photoshop CS5 and I certainly have an “artist’s view” when bringing an image to life. However, when it comes to these strong aurora scenes, the colors have not been saturated very much because Mother Nature did that work beautifully.
