January’s column was devoted to the blood moon and blue moon. This month, we have an interesting blue moon quandary. As mentioned in January, the length of our months are no longer set by the phases of the moon, rather they each have a fixed number of days. However, since the length of the month is so similar to the phases, we generally only see one full and one new moon a month. Months with a blue moon are the exception. They are months with two full moons, the second called the “blue moon.” The moon was last full on Jan. 2 and was full again 29.53 days later on Jan. 31.
This month, we end up with a similar situation. March 1 was the full moon, 29.53 days later, March 31 is another full moon. Clearly, we have a blue moon. As it turns out, that depends on whom you ask …
Two definitions exist for a blue moon, a monthly and a seasonal blue moon. The monthly blue moon is the definition given above, the second full moon in a month. However, the original definition for a blue moon comes from the Maine Farmer’s Almanac. In the 19th and 20th centuries, farmer’s almanacs across the mainland named each full moon within a season. The names generally were regional in nature and were based in either Native American or European tradition. We still see some of these names pop up today, like the Harvest Moon in September or the Strawberry Moon in June.
Let us take another look at the lunar cycle, this time focusing on seasons instead of months. Each season generally has three full moons (three months per season, one full moon per month). The original definition of a blue moon is the third of four full moons in one season, i.e. the seasonal blue moon. By that definition, the March 31 full moon is not a blue moon. Spring began 10 days before the full moon, making it the first full moon of the season.
Does it really matter if we call the March 31 moon a blue moon or not? Not really. Some people will and others will argue for the traditional seasonal definition. While our calendar is no longer dependent on the moon, many holidays remain based on the moon’s cycle. Chinese New Year for example generally falls on the second new moon after the winter solstice. Easter is the first Sunday after the first full moon after the first day of spring, April 1 this year. And the moon is the basis for the Hawaiian calendar.
Blue moon or not, go out and take a look at the full moon on March 31. You can never go wrong taking a moment to appreciate the clear night sky that we have here in North Hawaii.
We want to give a special shout out in this column to two North Hawaii students representing Honokaa High School at the State Science Fair. Hoku Sanchez and Keilani Steele placed second in the West Hawaii Science Fair science division and will be flying to Honolulu March 28 for the state fair. Good luck!