Orbs and the Blue Sky Glow

Photo date: June 4, 2016. Photographer: Mark Mahin.

The photo below shows a strange blue sky glow near a church in New York City, a blue sky glow that I have photographed several times before. Near the glow are some orbs, one of them quite bright.

There was no fog, mist, rain or precipitation when this photo was taken, or during the preceding 50 minutes.  The air quality listed on airnow.gov was "good," with a rating of 46.

This sky glow also appeared in several other photos I took at different spots this night. What was very strange is that when it first appeared in my photos, it was much lower in the sky.