What is an Equinox?
The word Equinox means “Equal Night”. Because the sun is positioned above the Equator, day and night are about equal in length all over the world during both Equinoxes. These brief but monumental moments are due to the 23.4 degree tilt of the Earth’s axis. We receive the Sun’s rays more directly in the summer because of the tilt. In the winter, we are tilted away from the Sun causing lower temperatures. Without the tilt of the Earth’s axis, there would be no variation in the length of day and night. The temperatures would remain the same throughout the year and we would not have seasons.
The word Equinox means “Equal Night”. Because the sun is positioned above the Equator, day and night are about equal in length all over the world during both Equinoxes. These brief but monumental moments are due to the 23.4 degree tilt of the Earth’s axis. We receive the Sun’s rays more directly in the summer because of the tilt. In the winter, we are tilted away from the Sun causing lower temperatures. Without the tilt of the Earth’s axis, there would be no variation in the length of day and night. The temperatures would remain the same throughout the year and we would not have seasons. WHAT IS A SOLSTICE? In the Northern Hemisphere the longest day and shortest night of the year occur, marking the beginning of Summer. It’s the reverse for the Southern Hemisphere. In March, the the Sun shines over the Tropic of Cancer at noon, above the Equator. In December, the the Sun shines over the Tropic of Capricorn at noon, below the Equator. During the two Solstices, the Sun is at its greatest
Because the axis of rotation of the Earth is tilted relative to the plane of its orbit, there are only two points in its orbit around the sun when the sun appears to be directly over the equator. On the days when the Earth passes through these points, there are nearly the same numbers of minutes of day as night everywhere on Earth. One of these days is called an equinox. To find these points geometrically, draw a line from the center of the sun to the center of the Earth and a line from the North pole to the South pole (the axis of rotation) of the Earth. The equinox locations are the only two points in our orbit where these lines are perpendicular.
An equinox is a period in the orbit of a plant in which the planet’s orbit and position cause the Sun to pass directly over the equator. In addition to being an astronomy event of note, the equinox also marks a shift in the seasons. On Earth, equinoxes appear around 22 September and 20 March every year, although the days can shift slightly, especially since the date is calculated using Coordinated Universal Time (UTC), which means that equinoxes in the Far East can fall a day or more later than equinoxes in Europe and the Americas, because of time differences. Every planet has a center line or equator, along with a celestial equator, an imaginary plane created by moving outwards from the equator. When the equinox occurs, the Sun is directly over the celestial equator, which means that someone standing at the equator would be able to see the Sun immediately overhead. It also means that half of the planet is fully illuminated, and that day and night are of roughly equal length. Given the
