Some cultures have names for each full moon during a year. The 1937 Maine Farmer’s Almanac lists the full moons “named by our early English ancestors.”
Winter Moons – Moon after Yule, Wolf Moon, Lenten Moon
Spring Moons – Egg Moon, Milk Moon, Flower Moon
Summer Moons – Hay Moon, Grain Moon, Fruit Moon
Fall Moons – Harvest Moon, Hunter’s Moon, Moon before Yule

The Harvest Moon is the only one I hear used any more. However, there is an occasional complication to this naming pattern. Because the lunar cycle is shorter than a calendar month, every so often, there are thirteen full moons during a seasonal cycle, giving one season four full moons. To keep the full moon names in sync with their appropriate seasonal activities, the third full moon was called a blue moon. We will have this kind of blue moon next year in 2010.

In 2010, the fall equinox occurs on September 22 and the winter solstice on December 21. Full moons occur on September 23, October 22, November 21, and December 21 (15 hours before the solstice). Therefore, the full moon on November 21 is called a blue moon under the old rule.

Given the circumstances, I think the last full moon of fall 2010 should be renamed the “Moon just before Yule.” As an added bonus it will also be a total lunar eclipse.

The lunar phases cycle is 29 1/2 days long. Since most months are 30 or 31 days long (Quick: How many months have only 28 days?), we see the lunar phases wander across the calendar, and once or twice a year we will have  2 occurrences of the same phase in the same month.

Ironically, this week I received an email from a friend containing a bunch of ‘interesting facts’ about this or that–most of which are totally un-interesting. Several people send me these types of emails that seem to circulate the internet every few years because I tend to research such trivia and usually debunk a lot of the material.

In this particular email appeared the following statement: “February 1865 is the only month in recorded history to not have a full moon.”

What??!! Paaa-lease! First of all, February, 1865 did have a full moon (on the 9th). I don’t know where/why/how 1865 got attached to this statement.

However, it is possible for February to not have a full moon; and this isn’t even a rare event. Remember that 29.5 day cycle? If we have a full moon on January 1st or 2nd, we will have another full moon at the end of January, and not see a full moon again until March, and then have 2 full moon’s in March as well. The last time this happened was 1999.

There was a full moon on January 2nd (Mountain time zone), January 31st, March 2nd and March 31st. Therefore, there was no full moon in February, 1999. A similar event happened in 1980, and it will happen again in 2018. Now, time zones and calculation rounding throws in a few oddities (like a blue moon happening in Utah, but not in Germany), but in general every 19 years we will have no full moon in February.

Oh, by the way, we will have a blue moon in 2009. The 2nd full moon in December occurs on December 31st, around noon, MST.