The Meaning of a Full Moon
14 Dec 2020
The full moon this month is on December 29, the 130th anniversary of the Wounded Knee Massacre. Since the 1890 massacre, there have only been two other full moons on December 29—in 1925 and 1944.
In 1890, the December full moon fell on Christmas Day. The preceding day, Big Foot and his followers “reached the White River about sundown,” according to Joseph Horn Cloud, a few miles west of what is now the town of Interior, just south of Badlands National Park. He said that the last members of their group crossed “after dark.” Sunset was at 4:20 PM, and the moon, which was nearly full, had risen at 3:11 PM, so they would have had lots of moonlight. They crossed in wagons, on horses, or by wading. Horn Cloud recorded that it “was windy, raw and cold.” The temperature had reached a high of only 23 degrees, and would fall to 10 degrees later that night. It is not surprising, therefore, that, as Horn Cloud mentions, “Big Foot was taken very sick with pneumonia” that night.
On Christmas Day, the travelers decided to move only about six miles. Dewey Beard, a brother of Joseph Horn Cloud, recorded that “Big Foot was very sick, and bleeding at the nose.” During the day the temperature warmed to 45 degrees, but fell to 12 degrees sometime after the full moon rose at 3:53 PM. Since then, there have been five full moons on Christmas Day: 1901, 1920, 1958, 1977, and 2015.
So how many years after 1890 before a full moon fell on every day of December? Incredibly, it was 121 years: December 10, 2011! If we work back in time from this year, it takes 68 years until the full moon falls on every day of December.
Clearly, the full moon is not on a regular pattern.
In astronomical terms, a full moon is when the sun, the earth, and the moon are aligned directly with each other in that order. Since the earth is constantly in motion around the sun, and the moon is constantly orbiting the earth, the full moon alignment is but a moment in time, and can occur any time during the night or day. The upcoming full moon, for instance, will happen at 9:28 PM on December 29, but it will look full when it rises at 4:24 PM. The following full moon, January 28, 2021, however, will occur at 1:16 PM, early that afternoon. But it will look full when it rises a few hours later at 4:53 PM. By the way, the times mentioned in this column are all Mountain Time Zone.
The period from full moon to full moon is called a synodic lunar month, and it occurs on average every 29.53 days. So how many full moons are there in a year? Well, it depends! This year, 2020, there will be 13 full moons. But next year there will be 12 and last year there were 12. In the past 20 years, 8 years have had 13 full moons. If we go 130 years back to 1890, 49 of them have 13 full moons.
Traditional Lakota culture divided a solar year into synodic lunar months or moons. So most years had 12 months, but about two out of every five years had 13 months. The Lakota year probably began with the first full moon of spring, about the time the ducks were returning from their winter homes in the south. “Magaksica Agli Wi” is the name for that month, which roughly corresponds to March or April in the Gregorian calendar.
In Lakota language, “wimima” denotes a full moon. It literally means a round moon. Since 11 of the 12 Gregorian months can have two full moons, whereas February sometimes has none, it is understandable why the names of Lakota moons do not directly align with the Gregorian months. The December full moon of 1890 could have been called Tahecapsun Wi (Deer Shed Their Antlers Moon) or Wanicokan Wi (Mid-Winter Moon).
Astronomically speaking, the moon phase between a Full Moon and the Third Quarter Moon is called a Waning Gibbous Moon. During this period, the moon’s illuminated face is diminishing from full to half. In Lakota language, this is the “Wi Makatanhan” period, when the moon “rises late and from the earth.” This was the moon phase when the U.S. soldiers massacred hundreds of children, women and men at Wounded Knee.
The next full moon would have been Wiotehika, “Hard Moon.” According to Buechel, “otehika” means “very hard to endure, trying, difficult.” The aftermath of the massacre was and remains otehika. We are reminded of this every year by the name of that Full Moon.
(This article is also published in Lakota Times.)