Because of Earth’s axis’ modest tilt to the Sun, various parts of the planet get varying amounts of sunlight at different times of the year, resulting in the changing of the seasons. Seasons and the requirement for equinoxes or solstices are caused by this tilt. Officially, the seasons change four times a year, with a designated point known as the equinox or solstice. While “solstices” refers to the change from spring to summer and fall to winter, “equinox” refers to the passage from winter to spring and summer to fall. It is essential to comprehend the distinction between equinoxes and solstices to comprehend seasonal variations and their varying relevance based on the hemisphere.
Inclination of Earth’s Axis and Orbital Plane
Worldwide differences in days and nights are caused by Earth’s tilt and orbit around the Sun. Seasons are caused by variations in the amount of sunshine that reaches each hemisphere for the year due to the Earth’s tilt, rotation, and elliptical orbit. The Northern Hemisphere enjoys summer when the top of the Earth is tilted towards the Sun, whereas the Southern Hemisphere faces away from the Sun and experiences winter.
There are two solstices and two equinoxes every year, which determine the seasons. Equinoxes occur at the two points in Earth’s orbit where the Sun appears directly over the equator, whereas solstices occur at the two points in the orbit when our globe is at its greatest tilt either towards or away from the Sun. The year is divided into four seasons by these cycles: spring, summer, autumn, and winter.
The tilt of the Earth influences the amount of direct light that reaches us from the Sun, resulting in the annual cycle of solstices, equinoxes, and seasons. In the UK, the longest day lasts 16 hours during the summer solstice, which happens when the Earth’s pole is inclined at its highest angle towards the Sun. The winter solstice in 2023 took place in December, marking the moment when the Sun reaches its most southern position in the sky and the North Pole is tilted at its greatest degree away from it.
What is an Equinox?
The exact times of day and night are known as equinoxes, and they fall on March 20–21 and September 22–23, respectively. The spring equinox happens on March 20 in the Northern Hemisphere, and the autumnal equinox arrives on September 22 or 23, which signifies the arrival of spring and fall. To prevent a bias towards the Northern Hemisphere, the terms “March equinox” and “September equinox” are occasionally employed. An equinox is one of two distinct times of the year when the sun is precisely overhead the celestial equator; it lasts for less than a day. The Latin term “equinoctial,” which means “the time of equal days and nights,” is where the word “equinox” originates.
What is a Solstice?
A solstice occurs when there is the greatest or least amount of daylight in a given day due to Earth’s tilt concerning the sun. It happens when the sun crosses the equator of Earth to its northernmost point on June 21 or its southernmost point on December 22. The summer solstice falls in June in the Northern Hemisphere and the winter solstice in December in the Southern Hemisphere. The solstices signify the beginning of summer and winter. The longest day of the year occurs on the summer solstice, while the shortest day occurs on the winter solstice, resulting in the longest duration of darkness. Originating in Latin, the word solstice refers to “the standing still of the sun.”
Difference Between Equinox and Solstice
Let’s examine the table below to have a deeper understanding of the distinctions between the equinox and solstice.
Equinox | Solstice |
Equinoxes are the equivalent of day and night. | Occurs when the quantity of daylight in a particular day is highest or least due to Earth’s tilt towards the sun. |
March 20–21 and September 22–23 are known as the equinoxes, which are equivalent times of day and night. | On June 21 or December 22, respectively, the sun crosses the equator to its northernmost or southernmost point, marking the solstice. |
In the Northern Hemisphere, the autumnal equinox falls on September 22 or 23, whereas the spring equinox falls on March 20. | The Northern Hemisphere’s summer solstice occurs in June, whereas the Southern Hemisphere’s winter solstice occurs in December. |
To minimise bias towards the Northern Hemisphere, the terms “March equinox” and “September equinox” are used instead. | With the longest day falling on the summer solstice and the shortest on the winter solstice, the solstices mark the start of summer and winter. |
Derived from “equinoctial,” which is Latin for “the time of equal days and nights.” | It is Latin in origin and means that the sun is not moving. |
Conclusion
The equinoxes and solstices are examples of seasonal variations brought about by Earth’s tilt and orbit around the Sun. The two points in Earth’s orbit where the Sun appears directly over the equator are known as the equinoxes, and the two places where the globe is tilted most either way towards or away from the Sun are known as the solstices. There are four distinct seasons in a year: spring, summer, autumn, and winter. The equinoxes cause the world to experience an equal amount of sunshine and darkness, while the summer and winter solstices provide the longest and shortest days of the year.
