Astronomical event: March Equinox 2021

24 Feb 2021

Are you ready for the astronomical event in March? Learn everything you need to know about the equinox taking place on Saturday the 20th of March 2021.

What is an equinox?

An equinox is plainly said the moment when the Sun is located exactly above the Earth’s equator. This moment occurs twice a year, in March and in September.

The origin of the word equinox is from the Latin word aequinoctium. This means “equal” and “night”. In the event of an equinox the daytime and nighttime are about the same duration all over the world. 

There are multiple terms for an equinox. For instance, in the Northern Hemisphere it is also called the March equinox, vernal equinox or spring equinox. The September equivalent is called the September equinox, autumnal equinox or fall equinox. 

Because the seasons in the Southern Hemisphere are the opposite from those on the Northern Hemisphere, the names are reversed. Hemisphere-neutral names are northward equinox for the March equinox and southward equinox for the September equinox. These names indicate the direction in which the Sun is crossing the equator. Either in a northward or southward direction.

What is the difference between an equinox and a solstice?

Some may confuse the equinox and solstice with each other. However, they can be seen as completely opposite of each other. The solstice is the time or date (twice each year) at which the Sun reaches its maximum or minimum declination. Therefore, while the solstices result in the change of the length of the night and day, equinoxes result in the equality of night and day across the earth. However, there are also some resemblances since both solstice and equinox take place twice a year.

The equinox conventionally marks the beginning of spring. In most cultures it is even considered the start of the New Year! For instance, the Assyrian calendar, Hindu and the Persian / Iranian calendars. 

Equinox and our Milky Way

On the day of the equinox, Saturday the 20th of March 2021, everywhere on Earth has almost exactly 12 hours of day and night. This happens as the Sun’s annual journey through the constellations carries it across the celestial equator.

Wherever you live on Earth, on the day of the equinox the Sun will rise from the point on the horizon which lies East, and set beneath the point which lies West.

Now that we know what an equinox means, it is interesting to look at our Milky Way and other planets on which an equinox may occur. Equinoxes can occur on any planet with a tilted rotational axis. For instance, the upcoming equinox of Saturn will take place in May of 2025. Additionally, the most recent equinox of planet Mars was on the 7th of February 2021.

Discover the March Equinox on Earth!

In this blog you’ve read all you need to know about the March Equinox, also known as the Northward Equinox. This astronomical event takes place on Saturday the 20th of March 2021. While this astronomical event may be difficult to view, it can also be used as the moment in time to celebrate the start of Spring (or Autumn depending on where you live). 

Want to celebrate by being able to view your own star in the night sky for at least 12 hours on the night of the equinox? 

Register your shining star!