The expression “Once in a blue moon” means that something is very rare. In astronomy, it means the third full Moon in a season with four full Moon or the second full Moon in a calendar month.
We experienced a blue moon on Friday, July 31, 2015. I was in France but friends back home sent me photos of the moon that night. They were so dreamy, I wanted to share them with you.
The next three were taken by Marilyn Scher on the roof of my New York coop.