23 February 2021

Light pillars and sun pillars - updated again


An Astronomy Picture of the Day from Finland, explained at the link and in my previous post on the subject.

Reposted from 2013 to add this awesome Astronomy Picture of the Day taken over Whitefish Bay:

"...vertical lines of light over a ground source that reflect from falling ice crystals. As the ground temperature was above freezing, the flat crystals likely melted as they approached the ground, creating a lower end to the vertical light pillars."
Reposted from 2018 to add this photo, via


And reposted yet again to add this remarkable image from the Astronomy Picture of the Day, which depicts a sun pillar.

"This was not a typical sun pillar. Just after sunrise two weeks ago in Providence, Rhode Island, USA, a photographer, looking out his window, was suddenly awestruck. The astonishment was caused by a sun pillar that fanned out at the top. Sun pillars, singular columns of light going up from the Sun, are themselves rare to see, and are known to be caused by sunlight reflecting from wobbling, hexagon-shaped ice-disks falling through Earth's atmosphere. Separately, upper tangent arcs are known to be caused by sunlight refracting through falling hexagon-shaped ice-tubes. Finding a sun pillar connected to an upper tangent arc is extraordinary, and, initially, took some analysis to figure out what was going on. A leading theory is that this sun pillar was also created, in a complex and unusual way, by falling ice tubes."
Might as well link to my previous posts on sun and light pillars in 2009 and 2010.

This schematic from Wikipedia -


- illustrates how the phenomenon is created.

7 comments:

  1. As a geologist in the oilfield of North Dakota we see an abundance of these when the conditions are right from the abundance of flares......

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  2. So cool. I don't often seen these, but do frequently spot sundogs and associated arcs.

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  3. I saw these on Christmas Eve heading south from Plattsburgh, NY. I was on the interstate and the pillars were coming from the headlights of the on coming cars. You could see them for miles, even around all the bends and hillocks of the road. Quite an amazing sight!! I've seen them before, but that was the most dramatic I've encountered.

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  4. I saw this APOD today (10.25.18) and was completely entranced by it ~

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  5. maybe you can add this photo of light pillars in texas (due to the recent cold snap there): https://twitter.com/WLBT/status/1361363396654989312

    I-)

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  6. Wow, that new APOD picture of the pillar+upper tangent arc is stunning! The term "ice tubes" is a little odd though, as it makes it sound like the ice crystals at play are somehow hollow. In reality, they are pillar-shaped, as explained on the Atmospheric Optics page they link to.

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