Evidence of Earliest Aurora Found in Ancient Chinese Texts

Such historical records of celestial events can help astronomers track and model patterns of space weather

An image of the northern lights over Lake Inari in Finland. The lights are a glowing green and purple.
an aurora borealis over Lake Inari in Finland Martincco via wikimedia commons under CC BY-SA 4.0

Scientists found evidence for the earliest record of an aurora, the colorful bands of light that dance in the sky, within an ancient Chinese text dated to about the tenth century B.C.E. In the Bamboo Annals, researchers found accounts of a five-colored light seen in the northern part of the night sky near the end of King Zhāo’s reign, the fourth king of the Zhou Dynasty, reports the Independent’s Vishwam Sankaran. The celestial event detailed in Advances in Space Research predates the previous reference of an aurora by three centuries.

The Bamboo Annals are a set of Chinese court records written on bamboo slips. They are some of the few records of the earliest period in Chinese history. They were found hidden in a tomb six miles southwest of the present-day city of Weihui in 279 C.E. Scholars have known about the bamboo slips for years, but a closer look at a section within the text about a celestial event in the sky led researchers to suspect it may be the earliest described aurora, reports Live Science’s Laura Geggel. The team suspects the text was written in either 977 B.C.E. or 957 B.C.E., but the exact year is unknown the Independent reports.

Auroras are fleeting streaks of luminant reddish or greenish light. They are often seen near Earth’s northern or southern magnetic pole and appear when electrically charged particles from the sun, traveling through the Earth’s magnetosphere, collide with gases, according to the National Oceanic and Atmospheric Administration

While the aurora borealis now is seen at northern latitudes, during the mid-tenth century B.C.E., the north magnetic pole was inclined toward the Eurasian continents, meaning that it was 15 degrees closer to central China than it is now, per Live Science. So individuals in central China, located as far as north of Beijing, could have witnessed the vibrant geomagnetic storms.

The aurora found in the Bamboo Annals is listed as a candidate aurora because the team does not have enough evidence to confirm an aurora. It took some time to make the finding within the ancient texts because in the 16th century a translation used the word comet instead of five-colored light, Live Science reports. Previously, the earliest known mentions of possible auroras were inscribed on cuneiform tablets by Assyrian astronomers between 679 and 655 B.C.E. Another record of an early aurora was found in the astronomical diary from 567 B.C.E. of Nebuchadnezzar II, a Babylonian king during the Neo-Babylonian empire, the Independent reports.

Tracking historical records of celestial events of auroras can aid researchers in understanding and modeling long-term patterns of space weather from decades to millennia, per the Independent.