A Sun Pillar
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.
Ice sometimes forms flat, stop-sign
shaped crystals as it falls from high-level
clouds.
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, the sun-pillar can be traced
up to the cloud that is raining the reflecting ice-crystals.