Byzantine Solar Eclipse Records Illuminate Obscure History of Earth's Rotation

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Witnessing a total solar eclipse is an unforgettable experience and may have been even more impressive throughout history before we were able to understand and accurately predict their occurrence. 

Witnessing a total solar eclipse is an unforgettable experience and may have been even more impressive throughout history before we were able to understand and accurately predict their occurrence. But the historical records of these remarkable astronomical spectacles are more than mere curiosities—they provide invaluable information on changes in the Earth's movement.

In a new study in Publications of the Astronomical Society of the Pacific, Japanese researchers combed through records from the Byzantine Empire to identify and locate total solar eclipses observed around the Eastern Mediterranean in the 4th-7th centuries CE, a period for which previously identified solar eclipse records are particularly scarce.

These records are crucial for understanding the variability of the Earth's rotation throughout history. However, because the people who recorded these events in antiquity often left out key information of interest to modern astronomers, identifying the correct times, locations, and extents of historical eclipses is painstaking work.

"Although original eyewitness accounts from this period have mostly been lost, quotations, translations, etc., recorded by later generations provide valuable information," co-author Assistant Professor Koji Murata of the University of Tsukuba explains. "In addition to reliable location and timing information, we needed confirmation of eclipse totality: daytime darkness to the extent that stars appeared in the sky. We were able to identify the probable times and locations of five total solar eclipses from the 4th to 7th centuries in the Eastern Mediterranean region, in 346, 418, 484, 601, and 693 CE."

Read more at University of Tsukuba

Image by: The New York Public Library Digital Collections