And the answer is...

These strange columns of light are created by ice crystals in the atmosphere. The light from the street is reflecting off ice crystals suspended in the air, bending the light toward the ground. Notice the white hoar frost on the trees in the foreground. That's also a sign of extreme cold and icy moisture in the air.

The picture above and the one shown in yesterday's post were taken in the western European city of Sigulda. But there have been reports of these strange atmospheric lights all over Europe the past few weeks. It's been very cold there, like it has been on our side of the globe. Ice crystals floating in the air helped create this beautiful show. Think of it as an icy fog.

We sometimes see a similar effect when sunlight or moonlight shines through ice crystals in upper atmospheric cirrus clouds. Sun dogs, halos, or parhelia, are quite common when the weather conditions are just right.