photo: Thomas Jacquin of Whitehorse
Also known as "false auroras," light pillars are 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.
"The different colors in this picture come from the various color temperatures of our street lights," explains Jacquin. "The warm orange ones come from traditional high pressure sodium lamps whereas the bright white pillars come from new LED lamps. While the new LED technology saves energy, it also increases light pollution and health concerns if the color temperature is not carefully selected. 3000K LEDs (warm yellow) are preferred over 4000K ones (bright white)."
Bron: http://spaceweather.com/ | Gewijzigd: 30 januari, 12:57 uur, door Joyce.s