In the winter of 773 AD, a comet hit the earth.

Japanese scientists discovered through the study of Cedar Carbon Fourteen that during the Tang Dynasty in China, the content of Carbon Fourteen in the earth's atmosphere suddenly increased strangely.

Extended data:

According to the records in Old Tang Book and New Tang Book, during the seven years of Tang Daizong Dali, a very spectacular comet phenomenon did appear.

There is a saying in the Chronicle of New Tang Dynasty Books: "In December of the seventh year of Dali, there was a long star in the DPRK. It exists forever. Long star, comet. "

"Old Tang Book" records: "[December of the seventh year of Dali] Bing Yin rainy soil, is the night star out of the ginseng." In the seventh year of Dali, the corresponding time of Bingyin in December was 65438+ 17 in 773 AD, which was very close to the beginning and season of the increase of coral carbon 14 content.

At that time, the astronomical phenomena hit by comets were spectacular. "At that time, the soil in Chang 'an was probably caused by the rupture of the comet nucleus. Its long day' also shows that the comet has entered the scope of the earth's atmosphere. "

He explained: "Researcher Sun, deputy director of the Institute of Natural Science History, Chinese Academy of Sciences, discovered these historical materials. In ancient China, attention was paid to the observation of astrology, and the comprehensive records of ancient astronomy often made foreign counterparts deeply envious. "

How big is this comet? Sun Weidong said that it was not large enough to compare with Halley's Comet. "If it is Halley's comet, it may increase the carbon content in the atmosphere by dozens or even hundreds of times, not just 1.5%.

It is estimated that Halley's comet lost about10.50 billion tons of matter when it passed the perihelion last time, and its carbon 14 may be close to the total carbon 14 in the atmosphere. "

References:

People's Network-Comet Hit the Earth? It was in the Tang Dynasty.