4 articles for "Equinox"
Equinox [Astro*Index]Literally, the time of equal day and night. This occurs twice each year, on or about March 21 (Vernal Equinox) and September 23 (Autumnal Equinox). This term is frequently, although incorrectly, used to describe a point lying on the Ecliptic.
See also:Equinox [Prima]
♦ Vernal Point ♦ Ecliptic
Refers to the point during the year when day and night are exactly equal in length. This occurs twice each year, on or about March 21 (Vernal Equinox) and September 23 (Autumnal Equinox). This term is frequently, although incorrectly, used to describe a point lying on the ecliptic (vernal point).
See also:Equinox [Munkasey M.]
♦ Vernal Point ♦ Ecliptic
This word literally means "The time of equal day and night".It is used in the sense of the "Aries Point", or the "Libra Point". See these entries.
See also:Equinox [DeVore]
♦ Aries Point ♦ Libra Point ♦ Vernal Point ♦ Ecliptic
A point in the Earth's annual orbit around the Sun, at which the polar inclination is at right angles to a line drawn between the Earth and the Sun; in consequence of which the length of the day and the night are equal all over the earth. This occurs at two points, called respectively the Vernal Equinox, which the Earth passes on March 21 when it enters Aries, and the Autumnal Equinox, on September 22nd when it enters Libra. Astronomers have not yet charted the Sun's orbit or determined its plane, or the inclination of the orbit of the Earth to that of the Sun, but it is possible that when these have been determined, it will be found that the Equinoctial points are the Earth's Nodes, where the plane of the Earth's orbit intersects that of the Sun. Thus the Zodiac, measured from the Spring Equinox, will be shown to represent a fixed relationship of the Earth and Sun in an orbit around some remote galactic center. (v. Galaxy.) This will make the Equinoctial points in reference to the Sun's orbit, analogous to the Moon's Nodes in reference to the Earth's orbit.
The equinoxes are commonly defined as the moment wherein the Sun reaches the point at which the plane of the ecliptic intersects the plane of the equator.
See also:
♦ Vernal Point ♦ Ecliptic
Astro*Index Copyright © 1997 Michael Erlewine