Comets – 彗星 Comets (彗星 Huìxīng) have been observed and recorded in China since the Shang Dynasty (1600-1046 BC). The set of comet illustrations shown above is from a silk book (帛书 Bóshū) written during the western Han period.
Cited by Hossein Turner at http://hozturner.blogspot.com.es/2013/07/the-great-comet.html
It is interesting to note the morphological similarities between those shapes and other petroglyphs around the world, especially if you invert the comet shapes. Keep in mind that this compilation of shapes have a normalized orientation. I do not know at this point if the original shapes from the silk book were all oriented like that. Nor if the depictions compiled there correspond to actual comet observations from the period (206 BC – 9 AD according to wikipedia) or from earlier times.
Hossein Turner’s thesis would imply that at least some of the recorded shapes that resemble plasma column instabilities might have come from comets instead of earth’s polar axis.