Nature’s magic
Cold conditions bring rare light show to area skies
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No, they were not ray beams from attacking space ships. Neither were they people being beamed up by the starship Enterprise. No, the strange lights seen streaming up into the sky around the area Nov. 23 were a rare weather phenomenon known as light pillars.
The light formation is a result of just the right combination of air temperature, moisture and angles of illumination.
Pillars appear when snow and ice crystals tilt in the sky to reflect light from a strong source forward. The thing that makes the phenomenon so rare is that it takes precise weather conditions to produce the kinds of ice crystals that make it work.
The key to light pillars are plate and column-shaped ice crystals.
Hexagonal-plate crystals are ice crystals consisting of six sides, as their name suggests. They resemble tiny dinner plates and are one source of the magic. Large plate crystals meet wind resistance as they fall to Earth, causing them to float with their horizontal axis parallel to the ground (like tiny flying saucers floating in the air).
Ice columns are more like small rectangles of ice that float through the air under the right conditions.
While the two may look nothing alike, plate crystals and ice columns do the same thing: reflect light.
Strong light from a ground source can be reflected off any surface of the ice crystals and will bounce back to the eyes of an observer. As the light passes upward through the crystals, the reflections are seen on the ground as a pillar of light extending upward into the sky. If viewed from elevation, or if the ice crystals are slightly off from perfect horizontal position, the reflection of the light off the top of the crystals can also produce light pillars the appear below the light source.
The intensity of the pillar depends on the brightness of the light and the concentration of crystals in the air. The color of the pillar will match the color of the source.
So, the question about light pillars is: Why are they so rare?
The answer to that question is that light pillars are rare because the conditions needed to produce the proper ice crystals are very specific.
Hexagonal-plate crystals only form when the air is between 32 and 25 degrees Fahrenheit and 14 to -4 degrees. Likewise, ice columns form when the air is between 23 and 18 degrees Fahrenheit and below -13 degrees.
With such specific conditions needed to produce the proper ice crystals, the formation of light pillars is not an easy thing to see.
So, the next time you are driving down the road on a cold winter evening and you see beams of light surrounding the countryside remember that there is no need to be frightened. Just sit back, relax and taken in one of nature’s many wonders.
