Hey Ray: Light pillars
PITTSBURGH (KDKA) - At night, when temperatures are exceptionally cold, a phenomenon can occur in the sky. Spikes of light, reaching high up! They look like beams shooting up into space, and these lights are called Light Pillars!
Light pillars need some very specific ingredients to form.
First, you need really cold temperatures.
Usually, temperatures fall below zero, but light pillars can occur with temperatures a little warmer than 0°F.
You will also want calm winds and high relative humidity levels. This creates tiny ice crystals that get suspended in the air. These ice crystals are plate or hexagonal-shaped.
According to NASA, usually, these ice crystals evaporate before reaching the ground. During freezing temperatures, however, flat, fluttering ice crystals may form near the ground in the form of light snow, sometimes known as a crystal fog.
Light from the surface hits the ice crystals and is refracted or bent upward.
The light keeps getting refracted through the ice crystals, and the higher the ice crystals are in the sky, the higher the light pillars can reach upward. Light pillars can come from above, too.
That sounds extraterrestrial, doesn't it?
According to the National Weather Service, the light pillars appear as vertical columns of light extending above or below the source of light, which can be streetlights, headlights on cars, or even the moon!