A light pillar is basically a visual phenomenon created by the reflection of light from ice crystals with near horizontal parallel planar surfaces. The light can come from the Sun (usually at or low to the horizon) in which case the phenomenon is called a sun pillar or solar pillar. Continue reading to see more.
5. A Sun Pillar Over Ontario
Photo credit: Rick Stankiewicz
What is that on the horizon? No, it's not an alien starship battling distant Earthlings, but rather a sun pillar. When driving across Ontario, Canada in early June, the photographer was surprised to encounter such an "eerie and beautiful" vista, and immediately took pictures. When the atmosphere is cold, ice sometimes forms flat six-sided crystals as it falls from high-level clouds.
4. A Sun Pillar Over North Carolina
Photo credit: Terry Holdsclaw
Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture taken in 2007 January, a sun-pillar reflects light from a Sun setting over Lake Norman, North Carolina, USA.
3. A Sun Pillar Over Sweden
Photo credit: Göran Strand
Light pillars have also been known to produce false UFO reports. Niagara Falls is one such area, where the mist from the Niagara Falls causes the phenomenon to appear frequently during the winter months, where the ice crystals interact with the city's many upward facing spotlights to create prominent light pillars. Light Pillars could also be formed by man made light sources.
2. Colorful Light Pillars
Photo credit: Walter Tape
How can an aurora appear so near the ground? Pictured above are not aurora but nearby light pillars, a local phenomenon that can appear as a distant one. During freezing temperatures, however, flat fluttering ice crystals may form near the ground in a form of light snow, sometimes known as a crystal fog. These ice crystals may then reflect ground lights in columns not unlike a Sun-pillar. In the above picture, the colorful lights causing the light pillars surround a ice-skating rink in Fairbanks, Alaska.
1. Unusual Light Pillars Over Latvia
Photo credit: Aigar Truhin
What's happening over that town? Close inspection shows these strange columns of light occur over bright lights, and so likely involve falling ice crystals reflecting back these lights. The above image and several similar images were taken with a standard digital camera in Sigulda, Latvia last month. The air was noted to be quite cold and indeed filled with small ice crystals, just the type known to create several awe-inspiring but well known sky phenomena such as light pillars, sun pillars, sun dogs, and moon halos.