Link to Masada
During the time period in which Masada is set, court astrologers were not uncommon. Vespasian, the emperor, favored an astrologer named Balibus. Earlier in his life, Balibus had encouraged Nero to kill many noblemen to appease the gods because of a passing comet, which heralds the demise of someone influential. Not only does this show how idiotic Roman society was at certain times, but also the great influence astrology and divination had on that time's culture.
Astrology was also present in Judea, where Masada actually took place. Well-learned individuals, such as Eleazar, would often know the constellations and local astrologers would gladly read your horoscope or divine the future. Although astrology was regarded in a more moderate degree in this region, its influences could still be felt.