The next full Moon is a near-total lunar eclipse, the Beaver, Frost/Frosty, or Snow Moon; Kartik Purnima, the full Moon of the Festivals of Karthika Deepam, Karthikai Vilakkidu, Thrikarthika, Loi Krathong, Bon Om Touk, and Tazaungdaing; and Ill (or Il) Poya.
The next full Moon will be early on Friday morning, Nov. 19, 2021, appearing opposite the Sun (in Earth-based longitude) at 3:58 a.m., EST.
While this will be on Friday for much of the Earth, it will be Thursday night from Alaska’s time zone westward to the International Date Line in the Pacific Ocean. The Moon will appear full for about three days around this time, from Wednesday night through Saturday morning.
Near-total lunar eclipse
The Moon will be so close to opposite the Sun on Nov. 19 that it will pass through the southern part of the shadow of the Earth for a nearly total lunar eclipse.
The partial shadow of the Earth will begin falling on the upper left part of the Moon at 1:02:09 a.m., EST, but the slight dimming of the Moon will not be noticeable until the full shadow of the Earth begins falling on the upper part of the Moon at 2:18:41 a.m. The arc of the shadow of the round Earth will spread across the Moon until the peak of the eclipse at 4:02:53 a.m. when over 97 percent of the Moon will be in full shadow and only a small sliver of the left side of the Moon will shine in the partial shadow of the Earth.
Because the Earth has an atmosphere, the full shadow of the Earth is not black. If you were on the Moon in this shadow and looking back at the Earth, you would see all of the Earth’s sunrises and sunsets falling on you and the surface around you, giving the Moon a reddish-brown color.
After the peak of the eclipse, the full shadow of the Earth will gradually move off the Moon to the lower right, completely emerging from the full shadow at 5:47:04 a.m. After this, the brightening of the Moon as it moves out of the partial shadow of the Earth will be difficult to notice, especially since morning twilight will begin at 5:54 a.m. The Moon will fully exit the partial shadow of the Earth at 7:03:38 a.m., just before the Moon sets on the west-northwestern horizon at 7:06 a.m.
One Moon, many names
The Maine Farmers’ Almanac began publishing Native American names for full Moons in the 1930s.
Over time these names have become widely known and used. According to this almanac, as the full Moon in Nov., this is the Beaver Moon, the Frost or Frosty Moon, or the Snow Moon. For the Beaver Moon, one interpretation is that mid-fall was the time to set beaver traps before the swamps freeze to ensure a supply of warm winter furs. Another interpretation suggests that the name Beaver Moon came from how active the beavers are in this season as they prepare for winter. The Frost, Frosty, or Snow Moon names come from the frosts and early snows that begin this time of year, particularly in northeastern North America.
Throughout Southeast Asia, numerous related festivals are celebrated around this full Moon. This is Kartik Purnima (the full Moon of the Hindu lunar month of Kartik) and is celebrated by Hindus, Jains, and Sikhs (each for different reasons). Karthika Deepam, also known as Karthikai Vilakkidu or Thrikarthika, is a festival observed by Hindus of Tamil Nadu, Sri Lanka, and Kerala when the nearly full Moon lines up with the Pleiades constellation (Krittika or Karttikai). Some areas celebrate multi-day festivals that include this full Moon.
In Thailand and nearby countries, this full Moon is the Loi Krathong festival, which includes decorating baskets and floating them on a river. In Cambodia, this full Moon corresponds with the three-day Bon Om Touk (“Boat Racing Festival”) or the Cambodian Water Festival featuring dragon boat races. In Myanmar, this is the Tazaungdaing Festival, a festival that predates the introduction of Buddhism and includes the launching of hot air balloons (sometimes flaming or laden with fireworks). In Sri Lanka this is the Ill (or Il) Poya, commemorating the Buddha’s ordination of sixty disciples as the first Buddhist missionaries.
The Moon’s connection to calendars
In most lunisolar calendars the months change with the new Moon and full Moons fall near the middle of the lunar months. This full Moon is near the middle of the 10th month of the Chinese calendar, Kislev in the Hebrew calendar, and Rabi al-Thani (also known as Rabi al-Akhir) in the Islamic calendar. Hanukkah begins on the 25th of Kislev, corresponding to sundown on Sunday, Nov. 28, 2021.
As usual, the wearing of suitably celebratory celestial attire is encouraged in honor of the full Moon.