North American residents have been dazzled by a number of colourful, vertical pillars of light that have appeared in the night sky.
Photographers from Ohio to Canada have captured these lights that range from orange to green, red, yellow and white. This is a rare sight throughout such Southern areas and is, arguably, one of the upsides to living in such arctic temperatures.
These light pillars typically occur in regions where the temperature becomes extremely cold. Flat ice crystals form in the air close to the ground and reflect both natural and artificial light, taking their color from the light source.
This light can originate from street or building lights that are illuminating the sky, appearing as an ascending beam of light. In normal winter conditions, numerous ice crystals are not found low enough to the ground to form the pillar of light. Light coming from the setting sun or the moon can also cause sun (or solar) pillars although this is rare.
As above, light travels into the atmosphere from a point source such as a street light. From there, it hits the hexagonal ice crystals which are often horizontally orientated. The light is then reflected off these numerous crystals which act as a mirror to the street light.
From the human eye, what we see is in fact an optical illusion. This is because a person can only see light rays that are directed at themselves, giving the impression of a pillar of light rather than an orb. You will experience a similar thing if you see a light source reflecting off a body of water.
Bright light pillars around Moncton City, New Brunswick, Canada, December 2017. Thanks to Sophie Melanson @CodiacSm #LightPillars #StormHour pic.twitter.com/VrnG5n9TLL
— #StormHour (@StormHour) January 7, 2018
https://twitter.com/mark_tarello/status/950915467677519878/photo/1
