Image 1 of 1
Sun Pillar Dawn
Last week this spectacular sunrise filled the eastern sky as seen from an overlook in the Bighorn Mountains. Even before the sun made it over the horizon, a pillar of light was shining above the sun, appearing like a flame. While sun pillars aren't that uncommon, it is rare for them to be as tall as this one. This optical phenomenon is caused by the collective glint of millions of flat hexagonal ice crystals slowly falling through the air. When they are aligned just right at sunrise or sunset, it forms a light pillar. Pillars can form above other bright light sources as well such as the moon and even streetlights when the air is cold enough.