Picture yourself standing in a quiet field. Snow crunches underfoot as you shift your weight, gazing towards the heavens. Your breath forms a frosty mist in the air. In the distance, a dogsled pulls its passenger over the frozen fields. Slowly, almost imperceptibly, the skies above begin to glow. Great rivers of color swirl high overhead and soon the entire sky appears on fire; an eerie greenish light casting shadows far below.