Described in “Nihon Shoki” red “pheasant tail”, which appeared in the sky over Japan in the VII century was most likely the Aurora. Today it is impossible to see over the country, but fifteen hundred years ago it was perhaps due to the fact that the magnetic latitude of Japan is different from today, reported in the journal Sokendai Review of Culture and Social Studies.
The oldest entry is about the astronomical event in Japan is found in “Nihon Shoki”, one of the oldest written monuments of the country. It says on a red sign with a length of more than 1 Jo (10 degrees), which appeared in the heavens on December 30 620 informed and shaped like a pheasant’s tail. Some researchers have suggested that the people of Japan observed a comet, but comets usually have a different color. Other scientists believed that the described phenomenon could be auroras, but it is usually more like a long winding ribbon, not the pheasant’s tail.
To put the point in this question, a team of researchers from the University of advanced studies SOKENDAI analyzed the literary description of astronomical phenomena, and studied the variety of possible shapes of the Aurora. In addition, the researchers determined the position of magnetic poles of the Earth in 620 to determine, could the glow of the upper layers to occur in the area of Japan at the time.
It was found that the magnetic latitude of Japan in 620 different from today: then, it was 33 degrees, while the now — 25 degrees. According to scientists, this means that at that time the inhabitants of the country could really observe the interaction between the solar wind and molecules of air in the upper atmosphere — especially because the length of the tail was about 10 degrees, which, as the researchers note, is consistent with the size of the Aurora. In addition, recent observations show that during strong magnetic storms can be observed fan-shaped lights that can be recalled is described in “Nihon Shoki” sign.
Thus, the researchers concluded that in the VII century in the skies over Japan appeared a rare red Aurora. In the future they plan to perform more sources for their scientific significance.
Recently, Japanese scientists managed to explain another phenomenon of pulsating auroras. It turned out, they start up the electrons released in the upper layers of Earth’s atmosphere due to the interaction with plasma waves in the magnetosphere of the planet.