According to astronomers, the supermoon phenomenon occurs when the Moon is closest to Earth in a elip rotation, making it appear about 7% larger and significantly brighter than average.
Nothing has changed on the entire Moon, its just that its closer to us, so it looks bigger and brighter, said Professor Catherine Pilachowski, honorary chairman of the Department of Astronomical Sciences Daniel Kirkwood at Indiana University (USA).
Depending on the geographical area, people in different countries can watch the super moon on the evening of October 6-7, local time.
According to Vietnam time, the October supermoon will reach its peak at 10:47 a.m. on Tuesday, October 7, 2025 (ie 11:47 a.m. on October 6, US East Coast time).
However, observers can see the brilliant round moon for about 3 consecutive days, from the night of October 6 to the night of October 8. When it first grows from the horizon, the typical yellow orange moonlight of autumn will spread across the sky - a moment likened to the "light harvest season" of the ancient farmers.
Professor Pilachowski further explained: The moment the full moon is in the blink of an eye, when the entire visible part of the Moon is lit up by the Sun. Before and after that time, only a small part of the Moon was obscured by darkness.
The name harvest moon originates from the Western agricultural tradition. This is the closest full moon to the fertilizer harvest time, helping farmers have more nightlight to harvest the crop.
Normally, the harvest month falls in September, but in 2025, it will appear in October, so this month is sometimes called the hunter month, marking the preparation period for the hunting and food storage season before winter.
According to Farmer's Almanac, the October harvest month is only the first supermoon in a series of three consecutive supermoons at the end of 2025. The next two times are November 5, 2025 - the super typhoon and December 4, 2025 - the cold super moon.
Professor Pilachowski said that the supermoon series often appear 3 consecutive times a year because the Moon's trajectory changes very slowly.
Meanwhile, according to astronomer Deborah Good (University of Montana, USA), the two supermoons of November and December 2025 will be the most notable, because at those two times, the Moon reaches its closest point to Earth on the most perfect day - making the moon the brighter, closer, and more difficult to take your eyes off.
In Vietnam, if the weather is favorable, sky-lovers can start observing the harvest super moon from around 5:30 p.m. to 6:30 p.m. on October 6, 2025, when the Moon gradually rises from the East. An ideal evening to watch the moon is in the sea or areas with little urban light - where the harvest moon shines brilliantly.
