One of Nature's Most
Spectacular Performances

One incredible benefit of being surrounded by miles and miles of Lake Michigan is the insulating nature it has against the effects of light pollution. There are no nearby metropolitan areas which effuse light and impede our ability to clearly see the stars and planets in the night sky. It’s no secret that when you are visiting Door County from your home in the city, the stars are brighter and the Milky Way is as bright as can be. Sometimes, if you are really lucky, you can also see the northern lights.

What are the Northern Lights?

Called the aurora borealis or “northern lights,” the eerie and enchanting ribbons of light in the night sky are a result of the collision of charged particles from the Sun and the Earth’s magnetic field. Solar wind sweeps energetic particles from the Sun towards Earth which are deflected by the terrestrial magnetic shield. However, some electrons are trapped in the magnetic field and are then accelerated toward the polar regions. The electrons strike the atmosphere to form the sometimes visible aurora.

The lights have given rise to many superstitions and stories over the millennia. They are magical to behold and are a rare sighting in the US.  In larger cities with light pollution, they are not visible, but in areas of the country where cities are distant, the lights can be spotted during times of high cosmic activity and when the sky is dark and cloudless.

Where in Door County can you see them?

Door County’s dark skies and low levels of light pollution, especially in the northernmost part, offer great opportunities to see the aurora borealis. The night must be cloudless and ideally absent of a bright moon. The best areas to view from are ones with a clear view of the northern sky.

A popular destination for stargazing and, thus watching for the northern lights, is Newport State Park. In 2017 the park was given a dark-sky designation, meaning it is on the international list of sites that offer an exceptionally clear view of the night sky due to low levels of light pollution. Since Newport State Park rests on the east side of the peninsula, the best areas to see the northern sky is toward the outer edge of the park.

When should I watch for them?

The phenomenon can happen any time during the year. There are dedicated apps and websites that can assist in helping you predict when you might be able to view them. Michelle Hefty, Newport State Park’s superintendent, also recommends two Facebook pages which regularly update followers with possible viewing timeframes: “Great Lakes Aurora Hunters,” and “Aurora Alerts by Soft Serve News.”

In order to know whether you have a chance of seeing an aurora, you need to know the level of geomagnetic activity at the time you are viewing. There is a simple index called Kp, a number from 0 to 9, which is used to refer to geomagnetic activity for a 3-hour period. The higher the Kp index, the more likely that aurora is visible. For viewers in the Door County area to have a high likelihood of seeing the Northern Lights, the Kp index would need to be higher than 5 or 6. You can see the estimated Kp levels here.

What should I look for?

The aurora comes in several different shapes; sometimes the forms are of many tall rays that look much like a curtain or folds of cloth. Earlier in the evening these rays can form arcs that stretch from horizon to horizon. Late in the evening, near midnight, the arcs often begin to twist and sway, just as if a wind were blowing on the curtains of light. Then in the early morning, the auroral forms can take on a more cloud-like appearance with patches blinking on and off repeatedly for hours, disappearing as the sun rises.

 

*All Photos Credit: Denny Moutray