was not based on observation of the sky above Japan. It seems to be centuries out of date, and it depicts the sky somewhere hundreds of miles to the west. Of the two most recent publications on the tomb, one puts the date at between 240 and 520 CE, the other between 120 and 40 BCE; both agree that it shows the sky above northern China, in the area of Xian and Loyang. A third Japanese researcher who lectured on the matter back in 1999 agreed with the 120 to 40 BCE date, but thought the location was in Korea.
Archaeology, as Belloq says, is not an exact science. But anyway the experts concur that whoever decorated this Japanese tomb was working from a manuscript centuries old and imported to the island from mainland Asia, a little glimpse into the cultural connections that brought Japan into the orbit of Chinese civilization.