What were those columns of light over Edmonton's sky?

Light pillars in Edmonton on Thursday, Nov. 21, 2024. (Credit: Nancy Brochu/Facebook)

Social media lit up with pictures of the evening sky over the Edmonton area late Thursday.

Weather conditions were just right for what are known as "light pillars."

The temperature needs to be just right, in the -11- to -13 C range, the wind has to be calm and there needs to just the right amount of moisture in the air to create ice crystals in the shape of hexagonal plates.

Those “plates” need to be oriented with the flat side facing down as they’re suspended in the air or slowly falling, so they can reflect the light coming off illuminated sources on the ground (street lights, building lights or even a setting sun).

This creates the illusion that the lights are being stretched high into the sky.

It’s a fairly rare phenomenon since conditions need to be perfect. If the ice crystals start to merge, you won’t get this affect. Or, if temperatures are a little warmer or colder, the ice crystals can form in different shapes.

Different orientations of ice crystals can also create other sky phenomena like Sun Dogs and Sun Halos.