CHIANG RAI – Residents in Northern Thailand gathered to witness a rare astronomical event: a total lunar eclipse, or “blood moon,” which happened to fall on the same day as the traditional Lanna festival, Sip Song Peng.
Many believe this day holds deep spiritual meaning as it is seen as a time when spirits are released. Fortunately, clear skies in several areas allowed people across the city to view the blood moon.
At the same time, families observed tradition by inviting monks to conduct religious ceremonies at home, offering alms and dedicating merit to their ancestors.
On the night of 7 September and into the early hours, the total lunar eclipse could be seen across Northern Thailand. The moon took on a striking reddish-orange colour, often called the “blood moon.” In Bangkok, the moon entered the Earth’s penumbra at 10:29 pm, moving into the umbra and beginning the partial eclipse at 11:27 pm.
The total eclipse lasted from 12:31 am to 1:53 am, a span of about 82 minutes. After that, the moon gradually came out of the Earth’s shadow, ending as a partial eclipse at 2:57 am, then leaving the penumbra and finishing at 3:55 am.
Night Sky Opens for Blood Moon
Earlier in the evening, rain and storms swept across central Chiang Mai and Mae Rim, covering the sky with clouds. By night, the clouds cleared in many neighbourhoods, giving residents a clear view of the eclipse. From around 10:30 pm, the moon gradually lost its brightness as it passed into the Earth’s shadow, reaching total eclipse by about 12:30 am and staying there for more than an hour.
During this time, the moon looked reddish-orange, which is why it’s called the blood moon. This colour appears because sunlight passing through the Earth’s atmosphere gets scattered. Blue light is filtered out, while only red light with its longer wavelength reaches and reflects off the moon, giving it that soft red glow.
In Chiang Rai, the blood moon event began around 11:28 PM local time on September 7, with the moon entering Earth’s penumbral shadow, followed by the partial eclipse phase. Totality, when the moon turned a striking reddish hue due to Rayleigh scattering, occurred between 1:30 AM and 2:52 AM on September 8, lasting 82 minutes. The blood moon concluded around 4:55 AM.
Supharerk Karuehanon, Assistant Director of the National Astronomical Research Institute, explained that a blood moon occurs when the sun, Earth, and moon line up, with the Earth between the other two. The moon passes into the Earth’s shadow only during a full moon, also known as the 15th night in the local calendar.
As the moon moves through the shadow, it first appears to darken, eventually becoming fully obscured before gradually leaving the shadow again. In Thailand, people used to call this event “Rahu swallowing the moon.”
This was the first total lunar eclipse, Blood Moon visible from Thailand in three years, with the last being in 2022. Apart from Thailand, people across much of Europe, Asia, Australia, Africa, the west of North America, the east of South America, and the polar regions could also observe.
Rahu Swallowing the Moon
This blood moon coincided with the Sip Song Peng festival, a long-standing Lanna tradition held each year on the 15th night of the 12th lunar month. According to legend from the Buddha’s time, King Bimbisara became a devout follower after listening to the Buddha’s teachings.
He regularly made offerings but never dedicated the merit to his departed relatives. This saddened his ghostly kin, who tried to make their presence known with eerie cries at night. The Buddha explained the cause, and from then on, the king dedicated merit every time he offered alms, ensuring his relatives benefited and were freed from suffering.
Sip Song Peng centres on making merit for the departed during the full moon of the twelfth lunar month in Northern Thailand. On this day, it is believed that Yama, the King of the Underworld, allows spirits to return to the world to receive merit from the living.
Families gather at temples to make special offerings. This tradition matches similar ceremonies elsewhere in Thailand, such as “Trut Sart” in the Central region, “Ching Pret” in the South, and “Bun Khao Pradap Din” in the Northeast.
Last night in Chiang Mai, communities like Baan Tha Duea in San Phi Suea continued to uphold these customs. Families invited monks to perform rituals at home. Food and offerings were carefully prepared for each deceased relative, sometimes with several sets according to the number of ancestors being honoured.
Each set included the names of the living and the departed, so monks could mention names accurately when giving blessings. Besides food offerings, it’s common to invite monks to share Buddhist teachings during the ceremony, so both the living and the spirits of past family members gain merit together.
