#EQUINOX DEFINITION FULL#

The word is derived from the Latin aequinoctium, from aequus (equal) and nox ( genitive noctis) (night). The instants of the equinoxes are currently defined to be when the apparent geocentric longitude of the Sun is 0В° and 180В°. In modern times, since the Moon (and to a lesser extent the planets) causes Earth's orbit to slightly vary from a perfect ellipse, the equinox is officially defined by the Sun's more regular ecliptic longitude rather than by its declination. Equivalently, this is the moment when Earth's rotation axis is directly perpendicular to the Sun-Earth line, tilting neither toward nor away from the Sun. More precisely, an equinox is traditionally defined as the time when the plane of Earth's equator passes through the geometric center of the Sun's disk. This occurs twice each year, around 20 March and 23 September. On the day of the equinox, the Sun appears to rise 'due east' and set 'due west'. This means that the day/night split of 12 hours in spring happens a few days before the equinox and in the fall, a few days after the equinox.Equinoxes and solstices on Earth eventДЄ solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator (rather than north or south of the equator). Since earthвЂ™s atmosphere refracts light, the suns top crescent can be seen a few minutes before actual sunrise and a few minutes after sunset. NOTE: The time of day is measured by when the first bit of light from the sun is visible (and disappears).

#EQUINOX DEFINITION FULL#

Since this tilt towards and away from the sun happens very gradually over the course of the entire year, there must be two points during that time period (between when the earth is tilted away and towards the sun) where the earthвЂ™s tilt is aligned in such a way that we receive equal parts day and night a full 12 hours each. The winter solstice is the day where we receive the shortest amount of day and the longest duration of night the sun being at its lowest in the sky. This is the day where the sun is at its highest in the sky, and we receive the longest amount of day with the shortest amount of night. When the earth is tilted at its maximum towards the sun, itвЂ™s called the summer solstice. The changing distances from the sun are too small to make any significant difference. This seems counterintuitive, but the distance the earth is relative to the sun has no significant effect on our climate.В As earth revolves around the sun, the tilt of the earth changes and is what provides us with the differences in seasons and the different amounts of of day and night we receive throughout the year. During the summer, weвЂ™re actually farther away from the sun than we are in the winter.

ItвЂ™s actually based on the tilt of earthвЂ™s axis.

To be exact, it actually takes the earth 365.24 days to make its full trip, which is why we have a leap year that accounts for the extra day we accumulate every four years.ДЇun Fact: The reason we have seasons is NOT based on the distance away from the sun. Our earth makes one full revolution, or trip around the sun in roughly 365 days. The astronomical reason we have seasons is because of earthвЂ™s path and the changing tilt towards and away from the sun.

Here we dive into those differences and why we see them. ( WROC) - While everyone changes seasons, Rochester and Upstate New York along with much of the northern half of the country truly experience the change of season.

Equinox definition