Definition

The various appearances of the MOON during different parts of the SYNODICAL MONTH. The CYCLE begins with new moon or change of the MOON at CONJUNCTION. The visible part of the waxing moon increases in size during the first half of the CYCLE until full moon appears at OPPOSITION, after which the visible part of the waning moon decreases for the remainder of the CYCLE. First quarter occurs when the waxing moon is at east QUADRATURE,last quarter when the waning moon is at west QUADRATURE. From last quarter to new and from new to first quarter the MOON is crescent; from first quarter to full and from full to last quarter it is gibbous.