An Homeric Eclipse
Our early ancestors marked the passage of years, not by a numerical reckoning, but by significant historical events. Thus, we are left to decide which of our numeric years coincides with "the fifteenth year of the reign of Tiberius Caesar," or "two hundred and thirty-nine years after the founding of the city of Rome." The latter standard of timekeeping was popular, since Rome dominated the world for many centuries. The expression, "ab urbe condita" ("from the founding of the city"), or simply a.u.c., is written often in ancient manuscripts. The founding of the city of Rome is conjectured to be April 21, 753 BC. This date is consistent with the necessary passage of years from the date of conception of its founders, Romulus and Remus, which was coincident with a solar eclipse on June 15, 763 BC. The inclusion of such astronomical facts in ancient texts allows us to establish dates with certainty.
Homer's Odyssey [1], a description of the adventures of Odysseus, the king of Ithaca, as he traveled home from the Trojan War, contains several astronomical references. One of these, a description of a solar eclipse in Book XX of the epic, allowed two astronomers to estimate the date of a described event, the slaughter of Penelope's suitors, as April 16, 1178 BC. This date is consistent with the established dates of the Trojan War (1192-1184 BC) [2-3].
This astronomical dating by Marcelo O. Magnasco of the Laboratory of Mathematical Physics at Rockefeller University (New York) and Constantino Baikouzis of the Observatorio Astronómico (La Plata, Argentina) was aided by the fact that total eclipses of the sun are infrequent. Since they are rare events, this is the likely reason why they are mentioned in ancient texts such as the Odyssey. The idea of dating the voyage of Odysseus this way is not a new idea. It was proposed in the 1920s, but there was no consensus between astronomers and historians as to which particular eclipse is described. Magnasco and Baikouzis consider not just the eclipse, but several other astronomical references. The constellation, Boötes, is mentioned, as well as the Pleiades star cluster (also known as the Seven Sisters), the planet, Venus, and the New Moon.
The New Moon reference is hardly helpful, since eclipses of the sun always happen at the time of the new moon. Venus is described as visible and high in the sky six days before Odysseus' vengeance. The Pleiades and Boötes are described as simultaneously visible at sunset, twenty-nine days before. Magnasco and Baikouzis speculate also that a trip by the god, Hermes, to Ogygia describes an astronomical event, since Hermes is identified with the planet, Mercury. Hermes' trip, thirty-three days prior to the event, is identified with the idea that Mercury was high in the sky at dawn at the western end of its trajectory. Hermes carried most of his messages west. An analysis of the ordering of these events with the eclipse for a span of years near the estimated date gave a firm date of April 16, 1178 BC.
Such dating is possible because of the regular solar system in which we live. In his analysis of ancient texts from many cultures, one classicist had the idea that our solar system was anything but regular. Immanuel Velikovsky (1895-1979), who help found the Hebrew University of Jerusalem, published Worlds in Collision in 1950. In this book, Mars and Venus step out of their orbits to nearly collide with Earth, and these close encounters are responsible for such ancient catastrophes as Noah's Flood.
References:
1. Homer, "The Odyssey," translated by Samuel Butler (MIT Classics).
2. Joseph Bonner, "Celestial clues hint at eclipse in Homer's Odyssey" (Rockefeller University Press Release, June 23, 2008).
3. Constantino
Baikouzis and Marcelo O. Magnasco, "Is an eclipse described in the
Odyssey?" Proc. Natl. Acad. Sci., vol. 105, no. 26 (July 1, 2008), pp.
8823-8828. Available as a PDF file here.