Planets are tilted slightly on their axis as it travel around the sun. This means different points on earth receive more or less sunlight throughout the year at different times. That’s how seasons change on earth. Depending upon the position of the Earth in its orbit with respect to the sun we have different seasons. If the Earth was not titled, we would have no seasons at all. And if the Earth would not rotate on its axis then we would not have day or night. In this article, we discuss the 7 differences between the equinox and solstice.
The equinox happens when the length of the day and night are equal. This happens twice a year once during September 22-23 and once on march 20-21. This actually happens when the center of the sun is directly above the equator.
On the other hand, a solstice happens when the day or night is the longest of the year. This happens twice a year once on December 21-22 and once on June 20-22. This happens due to the tilting of the Earth about its axis. At a specific point in orbit, the north pole seems to be titled closest to the Sun, giving the longest day or longest night. And at another point in the orbit, the south pole seems to be titled closest to the Sun.
The naming of the solstice and equinox may be different based on the hemisphere. The below image shows the 2 equinoxes and the 2 solstices that happen during the orbit of the Earth around the sun. You can understand the difference in the day and night durations during solstice and equinox by seeing the light exposure on the Earth in each hemisphere.
Difference between equinox and solstice
| Equinox | Solstice |
| Equinox is when day and night are of the same length in both hemispheres. This occurs twice a year. The Sun is exactly above the equator. | Solstice is when day and night are longer or shorter in both hemispheres. This occurs twice a year. |
| Equinox comes from the Latin word aequus which means equal and nox which means night. Not exactly equal but approximately. | Solstice comes from the Latin word Sol which means sun and sistere which means stationary or to stop. Either longest or shortest days. |
| The equinox happens twice a year when the center of the sun is directly above or in the same plane as the equator of the Earth. | A solstice happens twice a year due to the tilting of the Earth towards the Sun, once during the tilting of the north pole and once during the tilting of the south pole. In the summertime (in the northern hemisphere) north pole is tilted towards the sun, and later during winter(in the northern hemisphere), the south pole is inclined towards the sun. |
| Equinox is the time when the sun is near to equatorial plane which gives approximately equal lengths of day and night. | Solstice is the time when is far from the equatorial plane, therefore, making day and night long. |
| It occurs on March 22 and September 22 every year. | It occurs on June 21 and December 22 every year. |
| There are two types of equinoxes: March equinox: which is called vernal or spring equinox. (in the northern hemispheres) September equinox: which is called autumnal or fall equinox. (in the northern hemispheres) | There are two types of solstice: Winter solstice(in the northern hemisphere on December 22): Is the shortest day of the year. Summer solstice(in the northern hemisphere on June 21 ): It is the longest day of the year. |
| The southern hemisphere also has two equinoxes on these same dates. | In the southern hemisphere, it happens like the winter solstice in June and the summer solstice in December |
