Full Corn Moon Tonight to Set Stage for Rare Halloween Blue Moon Before Election

A full moon tonight will set the stage for a rare Blue Moon on Halloween, just three days before the presidential election on November 3.

The Full Corn Moon peaks on Wednesday, September 2, at 1.22 a.m. EDT. However, it will appear full until Thursday morning, NASA says.

Normally, September's full moon is known as the Harvest Moon because it is the closest full moon to the fall equinox, which takes place on September 22. This year, it falls early in the month, meaning the closest full moon to the equinox is on October 1, making this the Harvest Moon.

It also means October will have two full moons, with the next taking place on October 31—Halloween. When one month has two full moons, the second is known as a Blue Moon.

The fall equinox, or autumnal equinox, is one of two seasonal markers of the year, the other being Spring equinox. At this point, the day and night are almost exactly equal lengths—12 hours. In the Northern Hemisphere, this marks the point where nights start getting longer than the day. For countries in the Southern Hemisphere, it is the start of spring, with days getting progressively longer.

According to a blog post by NASA, September's full moon also corresponds with the Chinese Hungry Ghost Festival. "The seventh month of the Chinese calendar is the Ghost Month and the fifteenth day of this month (a full Moon day) is called Ghost Day, on which ghosts and spirits, including those of deceased ancestors, come out to visit the living."

For some Buddhists in Thailand and Bangladesh, this full moon is also known as the Honey Full Moon and the Honey-offering Festival. According to the legend associated with the festival, Buddha was trying to bring peace between two forest factions. During this time, he was fed by an elephant who brought fruit and a monkey who brought honeycomb.

According to The Old Farmer's Almanac, the Full Corn Moon gets its name as this was the time of year corn was traditionally harvested in the northeastern U.S. The last time there was a Full Corn Moon that was not also the Harvest Moon was 2017.

As well as being a Blue Moon, the second full moon in October is also known as the Hunter's Moon. This is supposedly named because it marks the time of the year when people needed to go hunting in preparation for winter.

October's Blue Moon also coincides with the Southern Taurid meteor shower, which peaks on October 10 but can be seen in the night sky until the middle of November.

full moon
A full moon seen in California in August. The full moon on September 2 will set the stage for two full moons in October. LUIS ROBAYO/AFP via Getty Images