The Aurora Borealis has brought visitors to Northern Europe for years, especially Finland, but these lights may find competition thanks to a new man-made phenomenon. Photographer Mika Wist captured photos of these new “urban light pillars” from his balcony when temperatures plunged to -19 °C / -2.2 °F earlier this week. So, what is causing these strange lights to occur?
What’s most surprising is that the artificial light show is actually caused by a combination of excessive light pollution and pillars of ice crystals trapped in the air. NASA’s Tony Phillips at Spaceweather explains how the light pillars are a very different breed from Aurora Borealis:
Lately, in communities around the Arctic Circle, people have been seeing colorful lights in the sky. Although they look like auroras, they are not… They’re light pillars, caused by ice crystals in the air which intercept urban lights and spread them into colorful columns. No solar activity is required for the phenomenon. The only ingredients are ice and light pollution.
Moreover, it’s possible that the subzero spotlights could form in your own city—provided you have excessive light pollution and a frigid climate, of course. In particular, you should keep an eye out for mini-light pillars that form in the glow of streetlights.
Images by Mika Wist