The term Black Moon has several definitions, but one of the most common definitions is the second new moon in a calendar month. This is similar to the well-known Blue Moon, which is the name given to the second full moon in a calendar month. Since it is a new moon, it will not be a visible event as the side of the moon that is illuminated will be facing away from the Earth.
The last time that two new moons fell in the same month was March of 2014. While some areas of the world, such as the United States, experience a Black Moon in September, it will not be the case for the entire world. “It’s the second new moon this month in all of the Americas, but not in Europe and points east from there,” said Bob Berman, an astronomer for Slooh. READ MORE
