Event #65: Giant comet stretched across the heavens at the birth of Mithradates; entire sky 'on fire'

This comet may have been one of the most spectacular of ancient times, with an extremely long tail and a brilliant maximum brightness. It was observed from China and Rome, and was apparently considered a portent of two events reported by writers in the latter country.

The Chinese text Han shu (100) is our primary source of dating for this “long-tailed” star. It says the comet was seen “in the east” sometime during the month of -124 August 31 to September 29, with a tail “stretching across the heavens.” It remained visible for 30 days. A more contemporary source, the Shih chi (-90) did not give details of the comet, but did note the reign period changed in -133 because of the appearance of a comet. A more recent Chinese text, the T’ung chien kang mu (1189), incorrectly claims the “long-tailed star” was seen in -133. It is possible that the “sparkling star” reported in the Han shu as seen in the north sometime during the month of -124 July 3 to August 1 might have been an earlier observation of this comet.

The Roman historians Lucius Annaeus Seneca and Marcus Junianus Justinus independently noted the appearance of a great comet as a portent to events discussed in their books. Seneca finished Quaestiones Naturales around 63 and at one point noted that during the reign of Attalus III, king of Pergamum, “a comet appeared, of moderate size at first. Then it rose up and spread out and went all the way to the equator, so that its vast extent equaled the region of the sky which is called the Milky Way.” Justinus wrote his abridgment of the earlier written Historiae Philippicae during the 3rd century. He said that when Mithradates VI Eupator was born “a comet burned so brightly for 70 days that the entire sky seemed to be on fire. In its greatness it filled a quarter of the heavens, and with its brilliance it outshone the sun, while its rising and setting each took a period of four hours.”

Previous treatments of the Roman comets were never truly decisive on the dates, mainly as a result of Seneca and Justinus not providing a definitive dating of the events described in their books. Historians have established the reign of Attalus III as extending from -137 to -132, while the probable date of the birth of Mithradates VI Eupator has been given as between -133 and -131. Although previous astronomers have listed the Roman comets separately from the Chinese comets, the Author believes that the descriptions are too similar to be ignored.

Full moon: July 17, August 15, September 14

135 BC, September, China, a tailed star comet appeared in the east stretching across the heavens. It lasted 30 days before leaving. (Ho, 39)

134 BC, September, China, a tailed star comet stretched across the heavens. Quite possibly this apparition is a confused transcription of the September 135 BC comet. Roman sources note that when the Greek Mithridates VI was born a comet shone for 70 days and the whole sky seemed to be ablaze.

(a) 6th year of the Jianyuan reign period of Emperor Wu of the Han Dynasty, 8th month; a star became fuzzy in the east that stretched across the sky.

(b) 6th year of the Jianyuan reign period of Emperor Wu of the Han Dynasty, 8th month; a long star emerged in the east, so long that it stretched across the sky; after 30 days, it departed.

NB: Ho (1962) lacked (b).

See also event #63 which may have been an earlier sighting of this comet as noted above in Kronk.