Description
Since early times, the succeeding alterations in the form of the moon were naturally noticed by humans, who tried to discover the regularity of the phenomenon, to describe and explain it. The lunar phases were named as follows: crescent moon, menoydes (lit., 'moon-shaped'); first or third quarter, dichotomos (lit., 'cut in half'); gibbous, amphikurtos (lit., 'curved in both sides'); and full moon, panselenos (lit., 'whole moon'). The diagram shows how astrologers thought about the moon in its circular movement with the Sun (the phases of the moon are dependent upon its relationship to the Sun), the crescent moon being the nearest to the Sun. Astronomically, a cycle goes from New Moon to New Moon. The luna conincta is the exact conjunction of Moon and Sun, that is, the Moon and Sun are at the same zodiacal degree.
Bibliography
Olaf Pedersen, 'In Quest of Sacrobosco', Journal for the History of Astronomy 16 (1985), 175-221 (p. 185)
