The following Moon names came into popular use more recently and do not refer to any specific month’s Moon:

• Blue Moon: Occasionally, two full Moons occur within the same calendar month. The first full Moon goes by the name normally assigned to that month’s full Moon, but the second full Moon is commonly called a Blue Moon. Blue Moons occur about every 2½ years. Another definition for “Blue Moon” is the third full Moon in a series of four full Moons occurring in a single astronomical season.
• Black Moon: The term “Black Moon” has a few definitions. Most commonly, it refers to the second new Moon occurring within a single calendar month; by this definition, a Black Moon can never occur in February. It has also been used to refer to a month in which there is no full Moon; this can only occur in February because the calendar month has fewer days (28 or 29 days) than the lunar month (about 29.5 days).
• Supermoon: A full Moon is said to be a “Supermoon” when it is at the point in its orbit closest to Earth. In astronomy, the terms “perigee syzygy” or “perigee full Moon” are typically used instead of “Supermoon.” .