International Astronomy Day 2021: Dates, History, Facts and Significance

Human mind is inquisitive. Themes like the extent of universe, space-time and existence of life beyond earth have always captured the central space in its curiosity. As a result, to study the objects  and phenomena beyond Earth, a specific branch of natural science called “Astronomy” was developed.

International Astronomy Day is celebrated as a bi-annual event with the aim to encourage more awareness about astronomy among common people and give them a platform to interact with professionals and scholars of this field.

International Astronomy Day is celebrated twice in a year —  once in spring and once in autumn. The International Astronomy Day also forms part of the National Astronomy Week which begins on the preceding Monday. At present, Astronomy Day is formally sponsored by many astronomy related organizations.

Did you Know? The word “Astronomy” has a Greek origin. It is formed by combining astro meaning star & nomia meaning law or culture. Thus, Astronomy means the law of the stars.

History of International Astronomy Day

In the year 1973, the then president of the Astronomical Association of Northern California, Doug Berger started the celebration of astronomy day. He wanted to set up various telescopes in and around the busy urban areas with an intention to encourage the passerby to enjoy the heavenly astronomical views.  This was the reason he started the celebration of Astronomy Day. The response this event received since its establishment has been remarkable. The event eventually expanded and attracted world-wide attention. Now many countries of the world celebrate Astronomy Day.

Biannual Astronomy Day

Unlike most international days which are usually annual events, the International Astronomy Day is Bi-annual or semi-annual event occurring in Spring and Autumn/Fall. There are no fixed dates as per the Gregorian calendar for Astronomy Day. The occurrence of bi-annual events is based on the lunar influence.

The Spring Astronomy Day usually occurs between mid-April & mid-May on a Saturday closest to the first quarter Moon. Similarly, the Autumn Astronomy Day occurs between September and October on a Saturday closest to the first quarter Moon.

Dates of World Astronomy Day in Coming Years

Year	Spring	Autumn
2020	02 May	26 September
2021	15 May	09 October
2022	07 May	01 October
2023	29 April	22 September
2024	18 May	12 October
2025	03 May	27 September

How do people celebrate International Astronomy Day?

The celebration of International Astronomy Day initially started in the United States but expanded widely in other countries. Organizations including educational institutions and planetariums celebrate the day by organizing various events, special documentary screenings, formal discussion forums, etc.

COVID-19 Pandemic & Astronomy Day in Spring 2021

All formal events associated with Spring Astronomy Day in 2021 have been canceled because of the global pandemic of COVID-19 virus. However, people have opted for virtual options to mark the occasion.