The Aurora Borealis is whimsical, pulsating constantly as it waxes and wanes in the night sky near the Arctic Circle. One moment the lights are invisible, obscured by overcast skies or just too weak to be seen with the naked eye. Then, they might suddenly explode across the sky into twists, ripples, or streams of luminous greens, yellows, reds, and even purple. The displays can last several minutes or change in a heart beat, dancing high in the heavens or flitting low near the horizon in elaborate patterns and streaks. On this night by Chena Lake near North Pole, Alaska (really! Santa is there, too!) last week, clouds began to move in as the whimsical lights danced low across the sky before disappearing behind a curtain of clouds.