If you’re someone who rejoices at every sign of fall, you might want to look at the moon this weekend.
Across the United States and especially in places with clear skies, a full moon will be visible, signaling that summer is nearing its end. Because of the way light travels through the atmosphere and the moon’s location on the horizon, the moon appears reddish-orange.
The Harvest Moon, whose name came from its usefulness to farmers harvesting crops in the fall before the advent of artificial lighting, will seem full for about three nights and is the full moon closest to the autumnal equinox of September 22 in the Northern Hemisphere. It started on Thursday evening and will be full on Sunday morning.
On Saturday evening at 8:23 p.m. east, the moon will appear four degrees above the eastern horizon, according to NASA. Jupiter will appear to the left of the moon, Saturn above the southeastern horizon and the Vega star, one of the brightest in our night sky, above the horizon.
According to NASA, Jupiter, Saturn and the stars will appear to shift west from the full moon every night. Jupiter will shine at its brightest on September 26 this year.
In New York City, Saturday night’s moon rises at about 7:45 p.m.; it will be visible there until about 6:30 a.m. on Sunday. In Houston, the moon will rise around 8:07 p.m. local time and set around 7:10 a.m. on Sunday. And in San Francisco, the moon will rise around 8:01 p.m. local time and set around 6:57 a.m. the next morning.
Full moons always rise opposite the sun close to sunset, which can give them a reddish-orange hue, said Kevin Lewis, an associate professor of planetary geophysics at Johns Hopkins University. “Anywhere with clear skies, you should have a great view,” he said.
The moon usually rises an average of 50 minutes later each day as it moves through its cycle, but during the harvest moon, the timing changes every night at a smaller interval, closer to 15 or 20 minutes depending on where you live, according to the Farmer’s Almanacthose farmers who would have given extra minutes in the days before the advent of artificial light.
The first known reference to the full moon as the harvest moon was in 1706, according to the Oxford English Dictionary, but cultures around the world have different terms for it and related traditions.
Algonquins in the northeastern United States called it the corn moon, “because this was the time to gather their main staple crops of corn, squash, squash, beans and wild rice,” according to NASA.
The full moon overlaps with the Mid-Autumn Festival celebrated in China, Vietnam and elsewhere, in part involving offerings to the moon goddess. In Japan, the moon is also called Imo Meigetsu, or the potato harvest moon, and sweet potatoes or taro may be offered alongside moon-gazing festivals.
The lunar phenomenon represents the beginning of the holiday Pitru Paksha, “a sacred event in Hindu culture when people remember their ancestors”, according to The Times of India. Some Buddhists will commemorate Madhu Purnima, or the honey offering festival.
More named full moons will appearing later this year: the Hunter’s Moon on October 9, Beaver Moon on November 8, and Cold Moon on December 7.