The lights along the flight line at Eielson Air Force Base, Alaska, shine under the Aurora Borealis, or Northern Lights, March 18, 2015. Eielson is home to RED FLAG-Alaska, a series of Pacific Air Forces commander-directed field training exercises for U.S. forces that provides joint offensive counter-air, interdiction, close air support, and large force employment training in a simulated combat environment. (U.S. Air Force photo by Staff Sgt. Shawn Nickel/Released)