Astrolabe Glossary and Notes


The points of intersection between the celestial equator and the ecliptic, the first point of Aries and the first point of Libra. At these points the sun’s apparent position is on the equator and represents the beginnings of spring and autumn. In 2005, the spring equinox occurred on 20 March, the autumnal equinox on 22 September. On these dates the length of day equals that of night, hence the name equinox.
MHS Home | Contact Us | ©2006 Museum of the History of Science