What to know

• A 2,700-year-old solar eclipse record from 709 BCE provided precise measurements of Earth's rotation speed in ancient times—data that would otherwise be impossible to obtain.
• The key breakthrough was correcting an eight-kilometer geographic error in the location of Qufu, the ancient Lu Duchy capital, which allowed the research team to accurately reconstruct the eclipse path.
• An ancient Chinese account describing the eclipsed Sun as "completely yellow above and below" may represent one of the earliest surviving written descriptions of the solar corona.
• The findings offer independent support for previous reconstructions of solar activity cycles based on radiocarbon measurements, suggesting the Sun was transitioning from a period of low activity.

“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.'”

Hisashi Hayakawa · Science Daily ↗ · Oct 25

Hisashi Hayakawa Lead researcher, Nagoya UniversityInternational research team Eclipse reconstruction researchers