Bear Lake, Alaska
This photo was taken by a U.S. Air Force airman who was stationed nearby. NASA explains that auroras occur most often when the sun is in the most intense phase of an 11-year sunspot cycle. Sunspots increase in number due to violent solar flare eruptions. This means more electrons and protons are added to the solar particles sent into the Earth’s atmosphere. Consequently, this brightens up the northern and southern lights considerably.