What is an astronmal equinox?

Answer 1

On earth, the equinox is when the Earth is in the postion of it's orbit around the sun so that the sun is directly over the equator (equinox, equator... get it). It occurs at Spring (March 21) and Fall (Sept 21).

Answer 2

There is no such thing. You probably mean the autumnal equinox. Because the Eatrth is tilted on its axis relative to its orbit around the Sun, the Sun shines on more of the northern hemisphere than the southern between March and September. It shines on more of the southern hemisphere from September to March. Around the 21st of September, the Sun crosses the equator headed south. This moment of the Sun's crossing the equator is the autumnal equinox. That day, and the vernal equinox in March are the only days when the day and night are equal length everywhere on Earth.

Answer 3

I think you mean astonomical equinox. It is the period in which the sun is located directly above the equator. It is called an equinox (which is Latin for "equal night") because it was once thought that on the equinox the length of day and night were equal. It happens on the first day of spring and fall.

Answer 4

You may possibly mean the "Autumnal" equinox. This is also known as the "Fall" Equinox. It occurs roughly around mid to late September, and is where both day time and night time are equal in length of time. This year the equinox will fall on September 23rd.

The other Equinox occurs in Spring (it is also called the Vernal Equinox) and occurs roughly around mid to late March. Again both day and night times are equal in length.

The link I've provided goes into more details on the types of Equinoxes (and their opposites, the Solstices), and times when they will each occur.

Answer 5

you mean an astronomical equinox i trust. it's the two times a year when day and night are of the same length. "equinox" is taken from latin, "aequus" means equal and "nox" means night. this happens when, from our point of view on earth, the sun passes over the equator. this happens on the 21st march, the first day of spring, and the 23rd of september, the first day of autumn. the other two seasonal changes are denoted by the sun hitting the tropic of cancer in the northern hemisphere (beginning of northern summer) and the tropic of capricorn in the southern hemisphere (beginning of northern winter).