A team of international researchers say they’ve uncovered new data on the world’s first recorded solar eclipse using a surprising source – ancient Chinese texts. These findings could help us understand more about the progression of the Earth’s rotation through the centuries.
The eclipse in question took place on July 17, 709 BCE, according to a chronicle titled “Spring and Autumn Annals.” The caveat here is that this record was compiled around two or three centuries after the eclipse happened.The chronicle comes from the court of Lu Duchy, a vassal state that existed during the Zhou dynasty.
“What makes this record special isn’t just its age, but also a later addendum in the ‘Hanshu’ (Book of Han) based on a quote written seven centuries after the eclipse. It describes the eclipsed sun as ‘completely yellow above and below,” lead author Hisashi Hayakawa,a researcher from Nagoya University in central Japan,said in a statement.
According to Hawakawa, this description has been historically associated with a solar corona – the outermost layer of the sun, which peaks out around the edges of the moon as the moon passes between the earth and sun during an eclipse. “If this is truly the case, it represents one of the earliest surviving written descriptions of the solar corona,” he said.
The team tried verifying the record of the eclipse by modeling the Earth’s rotation speed during this time. But they figured out that the eclipse wouldn’t be visible from Qufu, the capital city of Lu Duchy, where the chronicle was compiled.