Photo of Laser Pointer Through Rain Reveals Water Drop “Snowflakes”

On a rainy day recently, light painting photographer Jeremy Jackson was playing around with a green laser pointer when he discovered something interesting: all the out of focus raindrops in the photograph had a lined pattern in them — and each one was unique! These “water drop snowflakes” were found in all of the photos he took that day.

Anyone know what causes this phenomenon?

Image credit: Photograph by Jeremy Jackson and used with permission