March 20 Equinox Opens 2020 Lineup of Two Equinoxes and Two Solstices

Summary: The March 20 equinox opens the 2020 lineup of two equinoxes and two solstices that announce opposite seasons in the Northern and Southern Hemispheres.

Earth at instant of 2020 March equinox, which opens 2020 astronomical season Friday, March 20, 2019, at 03:50 Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Doman, via Fourmilab Switzerland

The March 20 equinox opens the 2020 lineup of two equinoxes and two solstices that announce opposite astronomical seasons in the Northern and Southern Hemispheres.

The year’s first equinox takes place Friday, March 20, 2020, at 3:50 Universal Time (Thursday, March 19, at 11:50 p.m. Eastern Daylight Time), according to the U.S. Naval Observatory Astronomical Applications Department website. The event signals spring in the Northern Hemisphere and autumn in the Southern Hemisphere.

The March equinox is known as the vernal, or spring, equinox in the Northern Hemisphere. The Southern Hemisphere knows the March equinox as an autumnal equinox.

Northward equinox is another name for the March equinox. The name recognizes the sun’s apparent crossing of the celestial equator, leaving the Southern Hemisphere and heading northward, according to Earth’s perspective.

Equinoxes and solstices alternate their occurrences during the year. An interval of approximately three months separates their occurrences.

Three months 17 hours 54 minutes after the March equinox, the 2020 June solstice takes place. The 2020 June solstice happens Saturday, June 20, at 21:44 UT (5:44 p.m. EDT).

The June solstice opens astronomical summer in the Northern Hemisphere and astronomical winter in the Southern Hemisphere. At the June solstice, the subsolar point coincides with the Northern Hemisphere’s Tropic of Cancer, located at 23.5 degrees north latitude. Earth’s subsolar point represents the point at which the sun appears to be at its zenith, directly overhead. The subsolar point experiences the sun’s rays as exactly perpendicular to Earth’s surface.

The Tropic of Cancer passes through three continents: Africa, Asia and North America. African countries on the Tropic of Cancer comprise Algeria, Egypt, Libya, Niger, Mauritania, Mali and Western Sahara. In Asia, the Tropic of Cancer passes through Bangladesh, China, India, Oman, Saudi Arabia, Taiwan and United Arab Emirates. The Commonwealth of the Bahamas and Mexico are the only two countries on the Tropic of Cancer in North America. is the only country in North America.

The 2020 September equinox makes its appearance 3 months 1 day 15 hours 47 minutes after June’s solstice. The 2020 September equinox occurs Tuesday, Sept. 22, at 13:31 UT (9:31 a.m. EDT).

The September equinox announces astronomical autumn in the Northern Hemisphere. The Southern Hemisphere knows the September equinox as spring’s opener.

Southward equinox is another name for the September equinox. Southward equinox references the sun’s apparent, southward crossing of the celestial equator.

The 2020 December solstice succeeds September’s equinox after an interval of 2 months 28 days 20 hours 31 minutes. The year’s second and last solstice begins Monday, Dec. 21, at 10:02 (5:02 a.m. Eastern Standard Time).

The end-of-the-year solstice signals astronomical winter in the Northern Hemisphere and astronomical summer in the Southern Hemisphere. At the December solstice, the subsolar point touches the Southern Hemisphere’s Tropic of Capricorn, located at 23.5 degrees south latitude.

The Tropic of Capricorn passes through three continents: Africa, Australia and South America. African countries on the Tropic of Capricorn comprise Botswana, Madagascar, Mozambique, Namibia and South Africa. The Tropic of Capricorn passes through three of Australia’s six states: Northern Territory, Queensland and Western Australia. Argentina, Brazil, Chile and Paraguay include the Tropic of Capricorn within their borders.

The tilt of Earth’s rotational axis accounts for the astronomical seasons announced by Earth’s annual quartet of two equinoxes and two solstices. The 23.5-degree axial tilt with respect to the plane of Earth’s orbit around the sun is responsible for the Northern Hemisphere’s orientation toward the sun and receipt of the most direct sunlight on the June solstice. Contrastingly, the tilt favors the Southern Hemisphere on the December solstice.

The takeaways for the March 20 equinox as opener of the 2020 lineup of two equinoxes and two solstices are that the event signals astronomical spring in the Northern Hemisphere and astronomical autumn in the Southern Hemisphere and that an interval of approximately three months separates the alternately occurring seasonal events.

Earth at instant of 2020 September equinox, which occurs as the year's second equinox, Tuesday, Sept. 22, at 13:31 Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Doman, via Fourmilab Switzerland

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Earth at instant of 2020 March equinox, which opens 2020 astronomical season Friday, March 20, 2019, at 03:50 Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Doman, via Fourmilab Switzerland @ https://www.fourmilab.ch/cgi-bin/Earth

Earth at instant of 2020 September equinox, which occurs as the year's second equinox, Tuesday, Sept. 22, at 13:31 Coordinated Universal Time: John Walker/Earth and Moon Viewer, Public Doman, via Fourmilab Switzerland @ https://www.fourmilab.ch/cgi-bin/Earth

For further information:

Marriner, Derdriu. “2019 June Solstice Happens Friday, June 21, or Saturday, June 22.” Earth and Space News. Wednesday, June 12, 2019.
Available @ https://earth-and-space-news.blogspot.com/2017/03/2017-spring-equinox-happens-monday.html

Marriner, Derdriu. “2019 Northern Hemisphere Spring Equinox Happens Wednesday, March 20.” Earth and Space News. Wednesday, March 13, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/03/2019-northern-hemisphere-spring-equinox.html

Marriner, Derdriu. “2019 September Equinox Happens Sunday, Sept. 22, or Monday, Sept. 23.” Earth and Space News. Wednesday, Sept. 11, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/09/2019-september-equinox-happens-sunday.html

Marriner, Derdriu. “2019 Winter Solstice Happens Sunday, Dec. 22, in Northern Hemisphere.” Earth and Space News. Wednesday, Dec. 11, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/2019-winter-solstice-happens-sunday-dec.html

Marriner, Derdriu. “December Signals Summer Solstice for American Samoa and Jarvis Island.” Earth and Space News. Wednesday, Dec. 18, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/december-signals-summer-solstice-for.html

Marriner, Derdriu. “June Signals Winter Solstice for American Samoa and Jarvis Island.” Earth and Space News. Wednesday, June 19, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/06/june-signals-winter-solstice-for.html

Marriner, Derdriu. “March Equinox Astronomically Opens Northern Spring and Southern Autumn.” Earth and Space News. Wednesday, March 6, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/03/march-equinox-astronomically-opens.html

Marriner, Derdriu. “March Signals Autumn Equinox for American Samoa and Jarvis Island.” Earth and Space News. Wednesday, March 20, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/03/march-signals-autumn-equinox-for.html

Marriner, Derdriu. “Northern Latitudes Have Least Amount of Daylight Near December Solstice.” Earth and Space News. Wednesday, Dec. 4, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/northern-latitudes-have-least-amount-of.html

Marriner, Derdriu. “September Signals Spring Equinox for American Samoa and Jarvis Island.” Earth and Space News. Wednesday, Sept. 18, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/09/september-signals-spring-equinox-for.html

U.S.N.O. Astronomical Applications Department. “Earth’s Seasons and Apsides.” U.S. Naval Observatory Astronomical Applications Department > Data Services > Equinoxes, Solstices, Perihelion, and Aphelion.
Available @ http://aa.usno.navy.mil/data/docs/EarthSeasons.php