Ancient Judaism and Christian Origins

Various Roman cults have special references to astronomy. For contemporaries, this is most evident in the external presentation of the corresponding works of art. They represent a popularizing short form of the cult. A nice example is the Mithras cult.
At the end of the 1st century it appears with many astronomical references. The name refers to the Persian Sun god Mithra. In Persia, however, there was no cult of the sun god Mithra that resembled the later Roman one. Merkelbach suspects that the cult was created by the environment of the imperial house. We see the idea of the cult in connection with the procession of Tiridate. The new Armenian ruler marched through the Roman Empire with a retinue of thousands of Parthian horsemen. In gold-decorated Rome he threw himself at Nero’s feet, worshipped him as his god Mithra and received his dominion from Nero. Through this propaganda coup a threatening war between Rome and Parthia for the rule in Armenia could be prevented. As a sign of the bond between the two nations there could have been an agreement that a Persian god should also be worshipped in Rome.
The cult image of the bull-killing Mithras poses a riddle. This image cannot be understood from Persian mythology – but from Roman imperial propaganda: In the Mithras relief the Sun god kills a bull that is curved to a (thick) crescent moon. The image is full of astral allusions. It is often framed by the zodiac, and the animals involved partly depict the celestial equator. The zodiac and the celestial equator together symbolize the whole cosmos, which is dominated by the Sun god. In the calendar system the Sun replaces the triad of Sun, Moon and stars. In a Babylonian leap year rule, which enjoyed widespread popularity, the thickness of the crescent moon in the Pleiades in the constellation of Taurus is used to refer to the necessity to insert a leap month. Thus the Sun, Moon and stars (especially the Pleiades) regulate the calendar and thus the order of the sky. However, this regulation had begun to collapse around 500 BC. Due to the precession of the earth’s axis, the validity of the leap year rule slowly moved from the spring month towards summer. An adjustment of the leap year rule in the spring month would have led to a thicker crescent moon than indicated in the Babylonian tradition. If one measures the cult pictures of the Mithras, then quite uniform “thicknesses” of the moon crescents from the bull body result. Converted into the age of the Moon they correspond to a Moon thickness which one would have adapted in this time for the Babylonian leap year rule – which would have been clearly wrong for all experts. Thus the cult image symbolizes to the initiate the “falling” leap year rule and thus the failure of the triad of Moon, Sun and stars. Only the Sun alone could be relied upon. The bull-killing Sun god Mithras kills his competitors and thus makes the change in the calendar and the heaven of the gods visible for all. Thus the Mithras cult supports the supremacy of the Sun over all other gods and thus also the legitimacy of the emperors, who increasingly relied on the Sun.