While we all love the long, bright days of June and July up in McCarthy, as summer comes to an end and nighttime creeps back into the evening, we are treated to one of the most amazing gifts Alaska has to offer: the aurora borealis, or Northern Lights.
The Northern Lights have inspired myths and legends from many cultures seeking to explain the fire in the night sky. Some societies believed that the Lights came from souls recently departed, human and animal. Others believed them to be the spirits of children or old maids dancing, or warriors battling in the sky. Today, we know that electrons and protons from the sun, carried on the solar wind, interact with the earth’s atmosphere where its magnetic field is weakest, near the northern and southern magnetic poles. In the Southern Hemisphere, the phenomenon is called the aurora australis.
The different colors of the Lights are determined by which gas particles the solar wind excites. Oxygen produces a green aurora in the lower layers of the earth’s atmosphere and a red aurora higher up. Nitrogen produces a blue aurora in the lower layers and a purplish-red aurora higher up. While the Lights can appear to be dancing just on top of the horizon, they are actually occurring 20 to 200 miles above the earth’s surface.
Due to its high latitude and total lack of light pollution, McCarthy is a wonderful place to watch the Northern Lights. The Lights are not visible every night in McCarthy, but your best bet for seeing them will be from 10pm-2am on a clear night from late August to September or from March to April. Powerful solar flares will increase the likelihood of seeing the Lights even at lower latitudes, and you can track solar activity with the University of Alaska – Fairbank’s Aurora Forecast. If the forecasted auroral index is 3 or higher and it’s not cloudy, it’s worth a look from McCarthy! So stay up late (or set your alarm!), bundle up and head outside to see the magic in science as the Lights dance and leap over Mt. Blackburn and the Stairway Icefall. It’s a breathtaking experience!