Great Conjunction - Great Conjunctions and History

Great Conjunctions and History

Great conjunctions are less spectacular than eclipses or comets but nevertheless they have also attracted considerable attention as celestial omens. During the late Middle age and the Renaissance they became a rather popular topic broached by most astronomers of the period up to the times of Tycho Brahe and Kepler, by scholastic thinkers as Roger Bacon or Pierre d'Ailly, and they are mentioned in popular and literary writing by authors such as Dante or Shakespeare. This interest is traced back in Europe to the translations from Arabian sources, most notably Albumasar's book on conjunction.

As successive great conjunctions occur nearly 120° apart, their appearances form a triangular pattern. In a series every fourth conjunction returns after some 60 years in the vicinity of the first. These returns are observed to be shifted by some 7-8°, so no more than four of them occur in the same zodiacal sign. To each sign astrologers have ascribed one from the series of four elements and thus four triplicities or 'trigons' are formed. Particular importance has been accorded to the occurrence of a great conjunction in a new trigon, which is bound to happen after some 200 years at most. Even greater importance was attributed to the beginning of a new cycle after all fours trigons had been visited, something which happens in about 800 years.

Originally a trigon was thought to last 240 years and the full cycle 960 years but later more correct estimation were provided by the Alphonsine tables. Despite the inaccuracies and some disagreement about the beginning of the cycle the belief in the significance of such events generated a stream of publications which grew steadily up to the end of the 16th c. As the great conjunction of 1583 was the last in the watery trigon it was widely supposed to herald apocalyptic changes; a papal bull against divinations was issued in 1586 and as nothing really significant had happened by 1603 with the advent of a new trigon, the public interest rapidly died.