Where Did the Name "Harvest Moon" Come From?

The three-day appearance of Harvest Moon started on Sep. 9, and everyone in Canada and the northern part of the US will be able to enjoy viewing this once-a-year event. But do you know why the moon is named this way? In this post, you'll learn the scientific explanation and even the cultural aspect of this full moon.

What is the Meaning Behind the Harvest Moon?

According to Almanac, the Harvest Moon is named for the fact that it appears in the early evening and provides a lot of strong moonlight, which has historically been useful for harvesting teams and farmers' summer-grown crops. The full moon closest to the beginning of autumn was given the name "harvest" because it coincides with when summer crops like corn are ready to be harvested.

According to an American folktale, each month's full moon has a unique name. Contrary to popular belief that NASA provides the names, it is the Algonquin and Iroquois tribes of North America that chose these names. They did so in order to connect changes in the landscape with changes in the sky in order to record the passing of the seasons.

While the now-out-of-print Maine Farmers' Almanac is the first American almanac credited with publishing Indigenous full moon names in the 1930s, today's almanacs, including The Farmers' Almanac and The Old Farmer's Almanac, still uphold the tradition. It is believed that colonial Americans then adopted these full moon names and used them in various texts.

Why Does the Harvest Moon Have Extra Moonlight?

During this time of year, the moon shines brightly in the early evening for several days in a row, providing harvesters with extra light to gather their harvests. Usually, following a full moon, the moon rises 50 minutes later and later each night, creating a period of darkness between sundown and moonrise.

The seasonal ecliptic, or the path the Moon takes across the sky as it moves through its monthly orbit around the Earth, has something to do with the longer period of moonlight during harvest moons.

The Moon advances eastward along the ecliptic as it orbits Earth in the northern hemisphere. Every night, it travels at the rate of what seems to be one fist held at arm's length, cutting across the eastern horizon at an angle with the earth.

This angle changes over the course of the year. Moonrise times vary greatly from night to night in spring since the moon's path steeply meets the horizon. The ecliptic, however, intersects the horizon at such a small angle that it is virtually parallel to the horizon during the weeks leading up to and following the autumnal equinox.

Because of this, the moon's position above the horizon varies the least from day to day (instead of successive moonrises occurring 50 to 75 minutes apart, there is a 20 to 30 minute lag) and the earth is illuminated by both twilight and moonlight for a number of consecutive nights.

According to Space, this month's Harvest Moon will be full at 5:59 a.m. Eastern Time on Saturday, September 10, two days after making a close pass to Saturn, Naval Observatory.

Check out more news and information on Space in Science Times.