Omen

[3] These omens include natural phenomena, for example an eclipse, abnormal births of animals (especially humans) and behaviour of the sacrificial lamb on its way to the slaughter.

[3] This belief of omens later spread out around the Near East and beyond when clay models of sheep livers used for the diviners to learn the craft was found in Boghazkoi, Ugarit, Megiddo, and Hazor.

[3] Letters from the city Mari dated at the latest from the 18th century showed that these divinatory practices were not limited to the royal court, but also played an important role in everyday life of the people.

Even since Homeric times, the Greeks paid special attention to these signs: when they saw vultures from the left, another symbol of Zeus, they considered it a bad omen.

In the Greek territory, seers also judged good and bad omens from the unwillingness or willingness of a victim to approach the altar and by the state of its offal when slaughtered.

Augurs also studied the behaviour of domesticated, sacred chickens before embarking on important enterprises, such as a senatorial meeting, the passage of a new law, or a battle.

Haruspices examined the liver, lungs and entrails of animals sacrifice to interpret the will of the gods, again in response to clear and specific proposals.

Some omens came in the form of prodigies – unnatural, aberrant or unusual phenomena such as meteor showers, hermaphrodite births, or "blood rain", any of which could signify that the gods had somehow been angered.

[5] The orator and statesman Cicero, though an augur himself, and apparently convinced that in capable hands, it offered a reliable means of foretelling the future,[8] was skeptical of unsolicited, personal omens.

[10] In the field of astrology, solar and lunar eclipses (along with the appearance of comets and to some extent the full moon) have often been considered omens of notable births, deaths, or other significant events throughout history in many societies.

Examples of omens from the Nuremberg Chronicle (1493): natural phenomena and unnatural births.
Manuscript of the mid-nineteenth century, possibly of Sgaw Karen origin, shows various appearances in the sun, the moon, clouds, etc., and indicates the primarily bad omens these appearances foretell. Explanations in English were added to this manuscript by a nineteenth-century American missionary. [ 1 ]
Halley's Comet 's appearance in 1066 was recorded on the Bayeux Tapestry . ISTI MIRANT STELLA literally means "These ones are looking in wonder at the star". National Geographic translated it in a 1966 article about the tapestry as "These men wonder at the star".