While there will be no issue enjoying the full moon on Chuseok night, those wanting to see the moon at its roundest will need to wait an extra day.
This year, Chuseok falls on September 25, which is the 15th day of the 8th month in the lunar calendar. In Seoul, the moon will rise at approximately 5:34 PM on that day.
However, the moment when the moon is at its roundest, known as 'mang' (望), will occur not on Chuseok itself but at 1:49 AM on September 27. 'Mang' refers to the time when the sun and moon are positioned directly opposite each other from Earth, typically indicating when the moon appears most circular.
Therefore, to catch the closest appearance of a full moon during Chuseok, it is advisable to look at the sky between the night of September 26 and the early morning of September 27. In Seoul, the moon will rise at 5:59 PM on September 26 and will reach its roundest point at 1:49 AM on September 27. The moon rising again on the evening of the 27th will have already passed this peak.
The reason the roundest moment of the moon occurs about two days after the 15th day of the lunar month is due to the way lunar dates are determined and the actual movement of the moon not aligning perfectly. The lunar calendar includes days when the moon is not visible, counting the first day of each month from the new moon. However, the time it takes for the moon to transition from the new moon to the full moon varies due to the elliptical nature of its orbit. As a result, 'mang' does not always align precisely with the 15th day of the lunar month, leading to a discrepancy of a day or more.
In celebration of Chuseok, events will be held in Seoul for direct moon observation. According to the city, the 'Full Moon Over Nanjido Pond' program will take place at Peace Park in World Cup Park from 6:30 PM to 9:30 PM on September 24 and 25. The event will accommodate both pre-registration and on-site registration.
* This article has been translated by AI.
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