Mysterious Sky Drifters

Photo date: April 6, 2015.  Photographer: Mark Mahin.

In this photo taken in Manhattan, we see more than a dozen orbs floating between two buildings.

There was no precipitation, fog, or mist on this night, and the air quality here (as listed on airnow.gov) was "fair" with a level of 55 that was close to the level of 49 that would qualify as "good."