The date and time when the sun crosses the equator. On that day, the daytime and nightime are both very close to 12 hours. This happens about March 21 and September 21. Many religious holy days are synchronized to the equinoxes, including the Jewish Passover, and Christian Easter. Wiccans, other Neopagans, Native Americans and followers of many aboriginal religions worldwide celebrate the equinoxes.
equinox: the spring and autumn midpoints, between the summer and winter solstices, in the Earth's elliptical orbit around the sun. These astronomical events were often celebrated in ancient traditions and incorporated in the building structures or statues that contained alignments to the position of the rising or setting sun during those specific dates in the yearly cycle. The solstices and equinoxes are/were measured by counting the days between the rising and setting positions of the sun on the horizon throughout the year, which change by swinging back and forth because of the tilt of the Earth.
The intersection of the ecliptic (apparent path of the sun) with the celestial equator. Vernal equinox is the intersection that the sun crosses about March 21; autumnal equinox denotes the crossing point about Sept. 21.
The time when the sun crosses the plane of the Earth's equator occurring about March 21 and September 22. During the Equinox, the day will have equal number (12) of daylight and nighttime hours.
The two times of year when the sun's position makes day and night of equal length in all parts of the Earth. They falls around the 21st of March and 21st of September.
See autumnal equinox and vernal equinox.
The time when the sun crosses the equator, making night and day of equal length in all parts of the world. Falls between March 2-22 and September 20-22.
instant in time when the subsolar point falls on the Earth’s equator and the circle of illumination passes through both poles
Two equinoxes occur each year, one when the sun crosses the celestial equator going north and one when the sun crosses the equator going south. For northern latitudes the March crossing is known as the vernal equinox, while the September crossing is known as the autumnal equinox.
An intersection of the ecliptic and the celestial equator. The center of the sun is geometrically above and below the horizon for equal lengths of time on the two days of the year when the sun passes the equinoxes; if the sun were a point and atmospheric refraction were absent, then day and night would be of equal length on those days.
Two periods when the declination of the sun is at the equator. The autumnal equinox occurs on September 22 or 23. The vernal equinox occurs on March 21 or 22.
Literally, equinox means "equal night," or the time when there is twelve hours of day and twelve hours of night. The Vernal and Autumnal Equinoxes mark the beginning of Spring and Autumn, respectively. A check of sunrise and sunset times, however, will reveal that on the first days of Spring and Autumn, there is actually slightly more than twelve hours of day. How then is the equinox actually reckoned? Since the celestial equator is inclined with respect to the ecliptic, these two lines (as seen from Earth) will intersect at two points. These two intersections are the Vernal Equinox and the Autumnal Equinox. The former is a point in the sky between the constellations Aquarius and Pisces, and the latter is between Leo and Virgo, 180 degrees away. As the Sun traverses along the ecliptic, it will pass through each equinox. The moment it does so is the time the season officially changes. (See also SOLSTICE). (See Figure 1)
either of the two points on the celestial sphere at which the ecliptic intersects the celestial equator; also the time at which the Sun passes through either of these intersection points; ie., when the apparent longitude (see apparent place; longitude, celestial) of the Sun is 0° or 180° . (See catalogue equinox; dynamical equinox for precise usage.)
from the Latin aequus meaning equal and nox meaning night. The equinox is when the day and night are an equal number of hours. When the Sun's rays are directly on the Equator.
The time at which the sun passes directly above the equator. In the Northern Hemisphere the vernal (spring) equinox falls on or near March 21st and the autumnal (fall) equinox September 21st. These dates are reversed in the Southern Hemisphere.
Either of the two points at which the Sun crosses the Celestial Equator, making day and night equal.
One of two days out of the year (September 22 and March 21) in which the Sun is directly overhead at noon at the equator.
(equinox). The moment when the direct rays of the sun cross the plane of the equator resulting in day and night being of equal length. The vernal equinox occurs about March 22 and the autumnal equinox about September 22.
The time of the year when the Earth is tilted on its axis directly above the equator, in March and September.
Literally, equal night. A day when the Sun is on the Celestial Equator, and its center is above the horizon half the time, and below the horizon half the time, making day and night of nearly equal length. Also, one of the two positions, the Vernal Equinox, and the Autumnal Equinox, where the Sun is on the Celestial Equator.
(astronomy) either of the two celestial points at which the celestial equator intersects the ecliptic
a moment when the Sun crosses the celestial equator
an astronomical point that occurs when the sun crosses the equator on its journey, and we experience a day and a night that are of equal length
Literally "equal night". it refers to the time of year when day and night are of equal length. (i) The positions where the centre of the Sun crosses the celestial equator. (ii) The dates when the declination of the Sun is zero (i.e. when it is on the celestial equator).
the point at which the sun crosses the equator and day and night are each 12 hours long: The equinox happens twice a year.
Means a time of equal day and night. This occurs twice a year and marks the beginning of Spring and Autumn.
Nodal point at which the ecliptic crosses the equinoctial (the spring and Autumnal equinoxes).
Two midpoints in the sun's yearly cycle. In the Northern Hemisphere, the vernal (spring) equinox occurs around March 21, the autumnal (fall) equinox around September 23. These are the days in the year when the hours of daylight and nighttime are equal.
The point in time when the vertical rays from the Sun are striking the equator. Around March 21st, the vernal equinox occurs and the autumnal equinox happens around September 22nd.
either of two points on the celestial sphere where the equator meets the ecliptic, representing the position of the sun when it is 90 degrees from the poles, or the two dates in the year when the sun is in this position in its annual cycle.
Literally "equal night" - the time in the Earth's year when the Sun crosses the equator and day and night are of equal duration. Sunrise and sunset are at the same time at all latitudes. This takes place during the spring (vernal equinox) and autumn/fall (autumnal equinox).
the time when the sun's path crosses earth's equatorial plane, or when the sun's declination is 0°. In the northern hemisphere, the vernal equinox, which occurs on or around 21 March, signals the start of spring. The autumnal equinox, around 22 September, is recognized as the beginning of fall (autumn).
the two points where the ecliptic intersects the celestial equator; when the Sun appears on the celestial equator
The time which marks the beginning of spring or autumn. The day that the equinox occurs has 12 hours of both daylight and darkness.
These points are defined on the celestial sphere as those at which the ecliptic crosses the celestial equator. The equinoxes are known as the autumnal and vernal (spring) equinoxes. The sun reaches the autumnal equinox at the beginning of autumn and the vernal equinox at the beginning of spring. The vernal equinox is used to define the point from which right ascension is measured. Halfway between the equinoxes lie the solstices.
The same word also refers to the moment when the sun crosses the point defined in (1). The autumnal equinox is on about September 22nd and the vernal equinox is on about March 21st every year. These dates vary slightly because of leap years. The days of the equinoxes are remarkable for having the same length of daylight as they have of darkness.
literally "equal night"; date on which the Sun crosses the celestial equator
A point where the Sun and ecliptic cross the celestial equator. The vernal equinox, when the Sun is moving northward along the ecliptic, is often referred to as the first day of spring in the Northern Hemisphere. The autumnal equinox, when the Sun is moving southward, is considered the first day autumn in the Northern Hemisphere.
Either of two times of the year when day and night lengths are approximately equal. Technically, it is one of two points at which the celestial equator intersects the ecliptic. See "vernal equinox" and "autumnal equinox."
One of the two times a year when the sun crosses the equator
The two times of the year when the sun crosses the equator and night and day are of equal length; usually occurs on March 21st (spring equinox) and September 23 (fall equinox).
This is the time when the Sun crosses the celestial equator. There are two equinoxes; Vernal (Spring), around March 21st and Autumnal (Autumn) around September 23rd. On these dates, day and night are equal. Actual dates and times vary due to the Earth's precession.
the two times of year when the sun crosses the celestial equator, giving day and night an equal 12-hour length everywhere on Earth.
("equal night") one of the two dates in the year when the length of the day equals the length of the night: the Vernal or Spring Equinox, which begins the "Bright Side of the Year", and the Autumnal or Fall Equinox which begins the "Dark Side of the Year"
The two points at which the Sun crosses the celestial equator in its yearly path in the sky. The equinoxes occur on or near March 21 and September 22. The equinoxes signal the start of the Spring and Autumn seasons.
the time when the sun crosses the equator and day and night are everywhere of equal length
The times when the sun crosses the equator. The two which occur each year are the Vernal equinox on March 20th, which is the beginning of spring, when the sun crosses from south to north and the Autumnal equinox on September 22nd, which is the beginning of autumn, when the sun crosses from north to south.The term equinox comes from 14th century Latin aequu s meaning 'equal' and nox meaning 'night' The equinoxes are two days in the year when the night and day are of equal length, and the only two days when the sun rises exactly in the east and sets in the west, when, for people on the equator, the sun is directly overhead at noon.
The twice-yearly occurrence (about March 21 and September 21) when the sun at its highest point crosses the equator.
Time of year when day and night are equal, and the sun is directly over the equator. Occurs twice a year at the Spring equinox (beginning of spring, around March 21) and the Fall equinox (beginning of autumn, around Sept. 21). These are the ideal times of year when the angle of an adjustable array should be changed from Winter tilt to Summer or back.
One of the intersections of the ecliptic and celestial equator; one of the two times during the year when the length of the day and night are the same.
Either of two points on the celestial sphere where the celestial equator intersects the ecliptic; either of the two times each year when the sun crosses the equator, and day and night are of equal length (spring equinox, fall equinox).
When the sun crosses the equator, making night and day of equal length in all parts of the earth. Vernal equinox occurs about March 21, while the Autumnal Equinox occurs about September 22.
Either of the two times each year when the sun crosses the equator and day and night are of equal length everywhere. During the spring (vernal) equinox (about March 21), it is said that an egg will stand on its small end. Although some people have reported success, it is not known whether such results were due to the equinox or to the peculiarities of that particular egg. Others insist that some eggs will stand on their small ends at any time of the year.
Equinoxes are days in which day and night are of equal duration. The two yearly equinoxes occur when the Sun crosses the celestial equator. The autumnal equinox occurs on September 23, 2003; the vernal equinox occurs on March 20, 2003.
Equal night. The point in the Earth's orbit around the Sun at which the day and night are equal in length.
occurs two times a year on March 21 or Sept. 23 where the day and night are of equal length.
this occurs when the center of the Sun is directly over Earth's equator. The Sun crosses the equator twice each year, once at the vernal equinox when it enters 0° Aries and again at the autumnal equinox when it enters 0° Libra. The days and nights are of equal duration all over the world on equinoctial dates. The vernal equinox occurs on the first day of spring, the autumnal equinox on the first day of autumn.
The time when the sun crosses the earth's equator, making night and day of approximately equal length all over the earth and occurring about March 21 (the spring or vernal equinox) and September 22 (autumnal equinox).
An equinox is defined as being when the sun passes through the celestial equator, ie it's declination is 0;. The vernal equinox, in northern spring, is when the sun moves from -ve dec to +ve dec, and the autumnal equinox the opposite. Due to precession, the point where the vernal equinox occurs, move by approximately 50 seconds of arc per year.
One of the two opposite points at which the sun crosses the celestial equator; when the days and nights are equal
Either of two times of the year when the sun crosses the plane of the earth's equator and day and night are of equal length. The vernal (spring) equinox occurs on March 21; the autumnal equinox occurs on September 21.
The vernal equinox of March 21, and the autumnal equinox September 21are points of the year when the sun rises due east and sets due west.
Roughly March 22 and September 22, when day and night are equal in length. They are celebrated (in the northern hemisphere) as the Sabbats of Eostara and Mabon. (see Sabbats)
Either of the two days when the periods of daylight and darkness are of equal length. The vernal equinox is usually March 21; the autumnal equinox is usually September 23.
The time of year when the Sun appears in the sky at the intersection of the ecliptic and the celestial equator. Two such points exist: The vernal equinox (approx. March 21) marks the start of spring. The autumnal equinox (approx. Sept. 20) marks the start of autumn. At each of these points, the Sun rises due east and sets due west. See also
Literally "equal night", a day when the number of hours of daylight equals the number of hours of night. The vernal equinox, usually March 21, signals the onset of Spring, while the autumnal equinox, usually September 21, signals the onset of Autumn.
The culminating point of spring or autumn. At the spring equinox, the earth's north pole is midway between the winter and summer solstices and entering into the warming trend of summer. At the autumnal equinox, the earth's noth pole is midway between the winter and summer solstices and entering into the cooling period of winter.
point on the sky where the ecliptic and the celestial equator intercept. When the Sun is at the equinox point, it is on the celestial equator and we have 12 hours of daylight. Vernal (spring) equinox: March 21; autumnal equinox: September 22.
The time when the Sun crosses the plane of the Earth's equator, making night and day approximately equal lengths all over the Earth. This occurs on or about March 21 (vernal or spring equinox) and September 22 (autumnal equinox).
either of the two points of intersection of the sun's apparent annual path and the plane of the earth's equator; in the northern hemisphere the spring (vernal) equinox falls on or about 21 March, and the autumnal equinox on or about 22 September.
Two points of intersection between the celestial equator and the ecliptic. These are the vernal equinox, through which the Sun passes on or about March 21, and the autumnal equinox, through which the Sun passes on about September 22.
Literally "equal night". In other words, in Spring (Vernal) or Autumn (Autumnal) when the daylight hours are equal to the darkness hours. Technically speaking, the point at which the ecliptic and celestial equator intersect.
Equal Night. Point in the ecliptic where the day and night is of equal duration. Vernal equinox is the first degree of Aries and the autumnal equinox is the first degree of Libra (these points are reversed in the southern hemisphere).
The point at which the ecliptic intersects the celestial equator. Days and nights are most nearly equal in duration. In the Northern Hemisphere, the vernal equinox falls on or about March 20 and the autumnal equinox on or about September 22. Related term: Dave's Dictionary
An equinox in astronomy is the event when the Sun can be observed to be directly above the equator. The event occurs twice a year, around March 20 and September 23. More technically, the equinox happens when the Sun is at one of two opposite points on the celestial sphere where the celestial equator and ecliptic intersect.