An omen is a phenomenon that is believed to foretell the future, often signifying the advent of change. It was commonly believed in ancient history, and still believed by some today, that omens bring
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.
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".
Augury was the Roman religious practice of observing the behavior of birds to receive omens. When the individual, known as the augur, read these signs, it was referred to as "taking the auspices". "Au
Roman augur with lituus, an augural wand, symbol of augurs and augury.