it's a diffraction corona

[Dave]

It can't be a glory as the colors are in the wrong order. Also most glories are
not as distict as his photo.

Otherwise, many of the same physical properties of a glory apply (bright
center region, shadow of obscuring object, etc.)

I do believe the powder on the ground is some sort of reflective medium
such as small glass beads or something like that.

The angle of incidence of the sun's rays on June 20 (summer solstice) in mid-day would be very nearly 90-degrees even as far north as MA resulting in a symmetrical display,

--Dave in Dallas

[Dan Cordell]

Please keep all discussion related to Dr. Lewin's challenge in this thread.