We earthlings love to look up at the moon. So much does the moon enamor us; we write movies, songs and poems by the droves that contain the name of the earth’s super satellite. A case in point is the fact that one of the biggest selling record albums of all time is Pink Floyd’s “Dark Side of the Moon.”
For all its romance inspiring awesomeness, the moon has another side to its personality. Werewolves, mood swings and even wild behavior are often blamed on the full moon. How many times have you heard the question acrimoniously asked, “is it a full moon tonight?”
Still, the moon is important and interesting to all of us who live in sight of its majestic beauty. We never tire wondering about it. In this article, we will talk about the moon, its cycles and the phenomenon known as the “blue moon.” Then, we will even give you a heads up as to when you can expect the next several full moons.
Full moons on different days
Where you live on earth rarely makes a difference as to whether the moon is full, quarter or new. This is because it takes the moon almost a month to travel around the earth and it only takes a day for the earth to turn around once. So in comparison, the moon sort of sits in the sky and waits for us to see what phase it is in. Still, there are times when the moon will be full on different calendar days in different areas of the earth.
Once in a blue moon
Technically, it takes the moon an average of 29.53 days to travel around the earth. Most months are longer than this. So, it is possible to have more than one full moon in one month. When this happens, the second moon is called a “calendar blue moon.” Of course, this is a simple rule. So, let’s complicate it!
The Farmer’s Almanac defines a blue moon as the third full moon in a season of four full moons. This is the correct definition of a blue moon. Since a season is three months long, most seasons will have three full moons. However, on occasion a season will have four. When this happens, the third is a true blue moon.
So here you have two definitions of a blue moon but the one for a calendar blue moon does not describe the true meaning of a blue moon. Here’s why:
On occasion February will have no next full moon and January and March will both have two. In this case, you have two calendar blue moons in the same year. However, there can be no more than one in a year’s time or it would not be that rare of an event. Using the Farmer’s Almanac description there can be a maximum of one in a year.
The moon’s orbit
The moon’s orbit is not on the same plane as the earth’s orbit around the sun. If it were, every time we had a new moon we would have a solar eclipse, and every time we had a full moon we would have a lunar eclipse. Instead, the moon travels in a track that goes well above and well below the earth. Still, on occasion it will travel in between the sun and the earth and in this case, there will be an eclipse.