Ancient Chinese Text Has Earliest Known Reference To Candidate Aurora

The study authors examined the mention of a "five-coloured light" seen in the northern part of the sky on a night towards the end of the reign of King Zhao of the Zhou dynasty.

New Delhi: An ancient Chinese text has the earliest known reference to a candidate aurora, according to a new study. The candidate aurora predates the next oldest one by around three centuries. 

This finding of the study, conducted by Marinus Anthony van der Sluijs, an independent researcher based in Canada, and Hisashi Hayakawa from the Nagoya University in Japan, was recently published in the journal Advances in Space Research.

The history of China from the earliest legendary time to the time of their probable composition, in the fourth century BCE, is chronicled in the Bamboo Annals, or Zhushu Jinian in Mandarin. Unusual observations and celestial events in the sky make an occasional appearance in the text, the study said.

“Five-Coloured Light” Mentioned In The Ancient Text

A fresh look at the ancient text yielded new insights. The study authors examined the mention of a "five-coloured light" seen in the northern part of the sky on a night towards the end of the reign of King Zhao of the Zhou dynasty, according to the paper. 

The exact year, however, is uncertain. The researchers settled on 977 and 957 BCE as the two most likely years.

The authors found the record of the "five-coloured light" to be consistent with a large geomagnetic storm, the study said. The mid-latitude aurora can present a spectacle of multiple colours when it is sufficiently bright.

Historical records much closer to our time have also documented celestial events like aurorae.

In the mid-10th century BCE, the Earth's magnetic pole was known to have been inclined to the Eurasian side, about 15 degrees closer to Central China than at present, the authors noted in the study.

As a result, the auroral oval could have been visible to observers in central China at times of significant magnetic disturbance. 

The study stated that this would be the earliest datable record of an aurora known from anywhere in the world. Two years before, several records of candidate aurorae inscribed on cuneiform tablets by Assyrian astronomers in the period 679-655 BCE were found. Cuneiform was a system of writing used in the ancient Middle East. The name is a coinage from Latin and Middle French roots meaning "wedge-shaped". Cuneiform was the most widespread and historically significant writing system in the ancient Middle East, according to Britannica. The Assyrians are an ethnic group of people who have lived in the Middle East since ancient times. 

According to the new study, some scientists have also associated Ezekiel's vision with auroral visibility in the Middle East. Ezekiel is acknowledged as a Hebrew prophet in Judaism, Christianity, and Islam. 

In the astronomical diary of the Babylonian King Nebuchadnezzar II, another interesting record of an early candidate aurora has been found. Nebuchadnezzar II was the second king of the Chaldean dynasty of Babylonia, and was known for his military might, the splendour of his capital, Babylon, and his important part in Jewish history.

Why Did Researchers Take So Long To Recognise The Aurora In The Five-Coloured Light Of The Chronicle Entry?

According to the study, one of the reasons why researchers took so long to recognise the aurora in the five-coloured light of the chronicle entry is that the Bamboo Annals had a chequered history. The original manuscript was lost, and then rediscovered in the third century CE. It was again lost during the Song dynasty.

A variant text was printed in the 16th century. In this text, the object in the sky was not a five-coloured light, but a comet. The new study has shown that this could not have been the original reading. 

According to the researchers, the fact that the popular descriptions of the northern lights can be pushed this far back in time is interesting in itself. 

Such historical information is valuable because it helps scientists model long-term patterns in space weather variability and solar activity.

By understanding these fluctuations, people can prepare for future solar eruptions of great magnitude and the disruption of technological infrastructure as a result of these violent activities.

According to the study, the record of an aurora candidate in the ancient Chinese text is now the only known historical reference to a space weather event before the Homeric Grand (Solar) Minimum (810-740 BCE). The Homeric Minimum is a grand solar minimum (regular period of least solar activity in the Sun's 11-year solar cycle) that took place between 2,880 and 2,550 years before present.