What happened
The records of the reign of King Gwanghaegun, part of the Annals of the Joseon Dynasty, preserve a report by the governor of Gangwon Province on events of the 25th day of the 8th lunar month of 1609 – September 22 in the Gregorian calendar. The governor collected reports from several counties where unusual objects had been seen in the sky between 9 a.m. and 3 p.m. The most frequently quoted description comes from Yangyang: a round, shining object resembling a washbasin reportedly rose above the house of a local official, turned red, and then split in two – one part flew off to the southeast, toward the sea, while the other stayed in place. Similar reports came in from several other localities in this mountainous province in the east of the Korean Peninsula. In the 21st century, the record became popular in South Korea as the “Joseon-era UFO.”
Witnesses
Residents and officials of several counties in Gangwon Province; the accounts were collected and sent to the royal court by the provincial governor.
Explanations and hypotheses
The Joseon Annals contain thousands of records of astronomical and atmospheric phenomena, because the court regarded them as signs from heaven. For the 1609 events, explanations such as a very bright daytime fireball, halo phenomena, or unusual clouds have been proposed, but the descriptions from several places and times do not fully fit any of them. Modern, sometimes loose translations of the text also raise doubts.
Unexplained There is no convincing explanation.