March Equinox 2020: Northern Spring, Southern Autumn
In 2020, the March equinox falls on Friday, March 20 at 03:50 GMT, which is 10:50 p.m. EDT on Thursday, March 19. Here’s all you need to know about this astronomical event.
What is equinox and why does it occur?
On Earth, there are two equinoxes in a year, in March and in September. The equinoxes are caused by Earth’s tilt on its axis and unceasing motion in orbit. Our planet normally orbits the Sun on an axis that is tilted 23.5 degrees, and daylight is distributed across the planet unequally. The Northern Hemisphere or the Southern Hemisphere receives more solar energy depending on where Earth is in its orbit around the Sun.
Twice a year, Earth’s orbit and the tilt of Earth’s axis combine in a way that the Sun shines directly on the equator and Earth is equally illuminated in the Northern and Southern Hemispheres. At this time, Earth's axis is tilted neither away from nor towards the Sun. These moments are called equinoxes and mark the change of seasons.
The March equinox marks the moment when the Sun crosses the celestial equator, traveling from south to north. In the Northern Hemisphere, the March equinox signals the end of winter and the beginning of astronomical spring and is called the vernal equinox. In the Southern Hemisphere, where seasons are reversed, the March equinox is known as the autumnal (fall) equinox and marks the end of summer and the beginning of autumn.
Did you know?
- The dates of equinoxes can vary. The March equinox falls on March 19, 20, or 21 every year, while the September equinox can occur on September 21, 22, 23 or 24.
- At the equinox, the length of night and day are nearly equal (12 hours) around the world. For this reason, this day was called “equinox”, which means “equal night” from Latin.
- On the day of the equinox, the Sun rises due east and sets due west, regardless of where you live. The exceptions are the North and South Poles, as there is no east or west there.
- All planets in the Solar system experience equinoxes and therefore have seasons. Some of them have four seasons like Earth. On March 20, Earth will join Venus and Jupiter as the only planets where it is now northern spring.
- Days around the equinox are perfect for observing the auroras (polar lights, northern lights, or southern lights) at high northern and southern latitudes.
- Equinox is a significant day for many cultures around the world. Higan, a Buddhist holiday, is celebrated in Japan during the March and September Equinox. The day of Easter is associated with the date of the March equinox. Nowruz, the Iranian (Persian) New Year takes place on the March Equinox, according to the Persian astronomical calendar.
Learn about the latest celestial events and astronomical news in the ‘What’s new’ section of the stargazing app Star Walk 2.