Equinox

Equinox
Related Category: Astronomy: General
(´kwnks), either of two points on the celestial sphere where the ecliptic and the celestial equator intersect.

Equinox
An equinox is one of two opposite points on the celestial sphere where the celestial equator and ecliptic intersect.

Equinox
From LoveToKnow 1911
EQUINOX (from the Lat. aequus, equal, and nox, night), a term used to express either the moment at which, or the point at which, the sun apparently crosses the celestial equator.

equinox
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Equinox
Lyrics and music: Phil Lesh
This is an oddity. It was written by Phil Lesh as a song to be sung by Jerry Garcia. It is often called "Mercy of a Fool" in bootleg lyric lists but it seems that "Equinox" is the correct title.

The autumnal equinox arrives on September 23. On this day the Sun rises due east and sets due west everywhere around the world, with everyone receiving equal hours of night and day.

Vernal Equinox
The vernal or spring equinox occurs around 21 March each year, although this is only spring for observers in the Northern Hemisphere.

On the equinoxes every place on the Earth sees the Sun rise exactly east and set exactly west! ...

Equinox is a twice-yearly event when the Sun lies directly above a planet's equator. For Saturn, this occurs every 15 Earth years and sees the Sun pass through the plane containing the giant planet's rings.

Equinox literally means "equal night". On the vernal (spring) and autumnal (fall) equinoxes, day and night are the same length.

Vernal Equinox
The date (near March 21 in the northern hemisphere) when night and day are nearly the same length and crosses the (i.e., 0) moving northward.

Precession of the Equinoxes
In astronomy, axial precession is a gravity-induced, slow and continuous change in the orientation of an astronomical body's rotational axis.

If you can stand an egg on its end on the Spring Equinox, surely you can on the Autumnal Equinox as well! Yet this always seems to get overlooked. That should be your first indication that something fishy is going on.

Equinox. Either of the two points (vernal, autumnal) on the celestial sphere where the ecliptic (which is the apparent path of the sun on the sky) intersects the celestial equator.

Equinox and Solstice
In particular (drawing above), the angle between the Earth's axis and the Earth-Sun line changes throughout the year.

equinox -- 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.

equinox See autumnal equinox and vernal equinox.
escape speed The speed necessary for an object to escape the gravitational pull of an object. Anything that moves away from the object with more than the escape speed will never return.

Equinox The two times of the year when the Sun crosses the celestial equator; vernal or spring equinox occurs about March 21st, and autumnal or fall equinox about September 22nd (northern hemisphere seasons).

equinox
the two times of year when the sun crosses the celestial equator, giving day and night an equal 12-hour length everywhere on Earth
escape velocity ...

equinoxes: (vernal or spring ~, autumnal or fall ~) literally 'equal nights' i.e. equal amounts of daylight and night-time.

Equinox -- The equinoxes are times at which the center of the Sun is directly above the Earth's equator. The day and night would be of equal length at that time, if the Sun were a point and not a disc, and if there were no atmospheric refraction.

Equinox- the two points at which the sun crosses the celestial equator; the spring equinox is about March 21, and the autumnal equinox is about September 22 ...

Equinox 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.

Equinox. The equinoxes are the two points at which the ecliptic intersects with the celestial equator.

Equinoxes occur twice a year, when the tilt of the Earth's axis is inclined neither away from nor toward the Sun, causing the Sun to be located vertically above a point on the equator....
power of eternally fighting bull (personifying the Earth ...

Equinox
(a) One of two points in the sky that represent where the Sun appears to cross the plane of the Earth's equator.

vernal equinox Date on which the Sun crosses the celestial equator moving northward, occurring on or near March 21.

Vernal Equinox
The point on the celestial sphere where the Sun crosses the Earth's equatorial plane from south to north. Also called the first point of Aries.

vernal equinox
The point along the ecliptic when the Sun crosses the celestial equator moving north. It occurs around March 21 and marks the first day of spring in the northern hemisphere.

vernal equinox: The place on the celestial sphere where the sun crosses the celestial equator moving northward; also, the time of year when the sun crosses this point, about March 21, and spring begins in the northern hemisphere.

Vernal Equinox - The point in the sky where the Sun appears to cross the celestial equator moving from south to north. This happens approximately on March 21 ...

Equinoxes
Equinoxes are days in which day and night are of equal duration. The two yearly equinoxes occur when the Sun crosses the celestial equator.

Equinox at midday, NZDT. Sun moves to the north of the equator
March 21
96% lit Moon 1.5° to upper right of Spica, αVirginis, evening sky.

equinox
On about 21 March & 23 September each year, the Sun is directly over the Equator causing equal hours of day & night.
galaxy ...

Equinox
March 21st, and September 22nd. Twice a year, when the day and night are the same amount of time all around the world.
Escape velocity ...

equinox - (n.)
An intersection of the ecliptic and the celestial equator.

see Equinoxes [A84]
Avalanche
A process such as that in which a single ionization leads to a large number of ions. The electrons and ions produced ionize more atoms, so that the number of ions multiplies quickly. [DC99]
Average Life ...

Vernal equinox
One result of this axis orientation is that, on average during the year, the polar regions of Uranus receive a greater energy input from the Sun than its equatorial regions.

Vernal Equinox 12 hours / 12 hours March 21
Summer Solstice longest / shortest June 21
Autumnal Equinox 12 hours / 12 hours September 21
Winter Solstice shortest / longest December 21 ...

AUTUMNAL EQUINOX
Equinoxes are days in which daytime and nighttime are of equal duration. The two yearly equinoxes occur when the Sun crosses the celestial equator.

AUTUMNAL EQUINOX - Point at which on the celestial sphere that the equator and the ecliptic intersect.

Chichen Itza Equinox
Ballcourt, from El Castillo
El Castillo (Spanish for "The Castle") is the nickname of a spectacular Mesoamerican step-pyramid that dominates the center of the Chichen Itza archaeological site in the Mexican state of Yucatán.

The Vernal Equinox
This is the origin of the "Age of Aquarius" celebrated in the musical Hair: a period when according to astrological mysticism and related hokum there will be unusual harmony and understanding in the world.

On the Vernal Equinox (or any other season start), what is the declination of the Sun? Where on the Earth would you have to be located to have it at your zenith?
How does the Sun move relative to the stars?
What is the ecliptic?

March equinox (NASA SP-7, 1965) = vernal equinox. mare (pl. maria) (NASA SP-7, 1965) Latin for sea. The large, dark, flat areas on the lunar surface, thought by early astronomers to be bodies of water.

Zodiac; Vernal Equinox; Circlet; wet quarter
Piscis Austrinus
Southern Fish ...

The two intersection points are the vernal equinox and autumnal equinox. The two points on the ecliptic which are farthest away from the equator are the summer solstice and winter solstice.

In former times the vernal equinox (i.e. the point where the Sun crosses the celestial equator when moving from the south to the north) lies within Aries, ...

The fix for the equinox was to define that years divisible by 100 will be leap years only if they are divisible by 400 as well. So, in the last millennium, 1600 and 2000 were leap years, but 1700, 1800 and 1900 were not.

March 20 - March Equinox. The March equinox occurs at 11:02 UTC. The Sun will shine directly on the equator and there will be nearly equal amounts of day and night throughout the world.

Precession of the equinoxes:
The axis of the earth's rotation slowly changes its direction, maintaining a constant tilt with respect to the ecliptic and making a complete rotation once every 26000 years.

celestial longitude (NASA SP-7, 1965) Angular distance east of the vernal equinox, along the ecliptic; ...

AUTUMNAL EQUINOX. The equinox that occurs in September. BARTEL'S ROTATION NUMBER. The serial number assigned to 27-day rotation periods of solar and geophysical parameters.

is seen in the evening sky and a planet at greatest western elongation is seen in the morning sky ephemeris a table of data arranged by date; typically tables of the positions of the Sun, Moon, planets and other solar system objects equinox ...

Harvest MoonThe Harvest Moon refers to the Full Moon that comes closest to the autumnal equinox, or the first day of autumn....Human Powered Clock DriveThink you need exotic materials and a machinist's know-how to get good astro photos?

Starting with the vernal equinox and then proceeding eastward along the ecliptic, each of the divisions is named for the constellation situated within its limits in the 2d century BC.

Hipparchus is best known for his discovery of the precessional movement of the equinoxes; i.e.

First, the star Antares (RA 16h 29m) is a bright red star, which anciently marked the autumnal equinox, that is, the place in the sky where the sun appears on the first day of autumn.

Similar to terrestrial seasons, the Ls system is reckoned directly from the Sun's ascending node or Martian northern spring equinox position, where Ls = 0°. Each beginning season is 90° from the next one, e.g.

is the location astronomers chose to mark the vernal equinox, which is where the ecliptic intersects the celestial equator, as the Sun crosses over from the southern celestial hemisphere to the northern celestial hemisphere.