And remember it’s a “seasonal” Blue Moon … the third of four full moons in a season, coming up on the night of August 20-21.
So maybe you’re saying, “But I thought a Blue Moon was the second full moon of a month.”
Yes, it is. The name Blue Moon is part of folklore. Like all folklore, there are alternate versions of the story.
A Blue Moon can be the second of two full moons of a calendar month. Or a Blue Moon can be the third of four full moons in a season. The upcoming Blue Moon is the seasonal kind. A “season” in this case is between the June solstice and September equinox.Here’s more.
Thank you to EarthSky Facebook friend VegaStar Carpentier for this image!