International Day of Planetariums
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International Day of Planetariums logoThe second Sunday in March:
Let's celebrate planetariums around the world!

Next date: March 11, 2018

 New: Special focus on portable domes for 2018! Read more here.


The International Day of Planetaria (IDP) was born in Italy in 1995. Conceived by the Associazione Amici dei Planetari, it became truly an international day in 1995, when other planetariums in Europe joined in the celebration. Today it is celebrated in the United States and Australia as well, and hopes are that it will continue to grow and encompass the globe. Many locations use this day as a kick off event or the culminating day of a week of special programming and activities for the public.

The goal of IDP is to involve the international planetarium community in a collaboration that promotes knowledge of planetariums to the public.

Originally scheduled for the Sunday before the spring equinox, later the date was set as the second Sunday in March to allow planetariums to more easily schedule in advance.

All planetariums, regardless of affiliation, are invited to take part. Facilities that typically have an admission charge are urged to make the day a “free” day for their communities.

Planetariums are Important

Why are planetariums important? In today’s light-polluted world, many people have lost touch with the stars. Only a few can be seen over large cities, and even in some rural areas light encroachment hides the stars of the Milky Way. Planetariums were developed to “capture the stars” and bring them to Earth so that everyone could enjoy and learn about them.

According to the latest unofficial figures, each year 144,012,579 people visit the 4,145 planetariums in the world.
(Ref: Loch Ness Productions,

The goal of IDP is to increase that number by informing as many people as possible that planetariums exist and that learning about the stars, space exploration, and astronomy is an enjoyable life-long activity.

Specific Goals of the International Day of Planetaria:

  1. to inform the public about planetariums: what they are and why they exist;
  2. to educate the public about the problem of light pollution;
  3. to promote international exchanges and collaborations between planetariums of different countries;
  4. to highlight the important work of the International Planetarium Society.

The first goal is easy to meet simply by holding the IDP event. To help with publicity, see a sample media release

Suggestions about meeting goal 2, the problem of light pollution, include obtaining public outreach literature from the International Dark Sky Association; obtaining the program Losing the Dark (in fulldome or flatscreen), which can be downloaded from the IDS site at; collaborating with a nearby dark sky reserve or sanctuary; collaborating with a local amateur astronomical society; and more.

To meet the fourth goal, participating planetariums may display a sign reading “The ____ Planetarium is a proud member of IPS.”

This leaves the third goal, the promotion of international exchanges and thus, the next topic:

Changes coming in 2018

In 2018, the name of the effort will change to International Day of Planetariums*, and the observation will be changed with the option of celebrating the day on either the Saturday or Sunday of the second weekend of March to allow domes that are not open on Sundays to also take part.

In addition, to enhance the international aspect of the day, a partnership program will start. Because the IDP is sponsored by the International Planetarium Society, the IPS will work to obtain a list of all planetariums around the globe who are interested in taking part.

Just as every nation is joined under the vault of the stars overhead, planetariums are joined in spirit and purpose under one dome. To celebrate this fact, planetariums taking part will partner with another facility elsewhere in the world. For example, a planetarium from an Italian city will work with a planetarium in a city from Africa, another country in Europe, Asia, or the USA. 

The partnership can be as simple as sharing photos of the planetarium and surrounding community; using clips from the Voices from the Dome project; producing a program from the Pages of Stars contest; or downloading and presenting Losing the Dark in the language of the partner planetarium.

Planetariums that serve immigrant and other under-represented populations may select a partner planetarium that reflects the makeup of their community. A planetarium in Texas or any of the US states that border Mexico might plan a “hands across the border” IDP event with a planetarium in Mexico, for example.

If possible, have local high school or college students write letters in a language they are studying and exchange them with students in the applicable country; perhaps they could write about a constellation story or myth.

For younger students, partner planetariums could match classrooms and have the students draw and exchange pictures of something in the sky, complete with labels or descriptions in their native languages.

For adults, partnership with a citizen science project like Globe at Night might be considered.

Taking collaboration further

After the first partnership IDP, the IPS will survey those taking part and collect information about what worked and what didn’t work. If a planetarium produced material just for the day, we will seek permission to share the material online for others to download.

For more information and/or to volunteer as a partner planetarium, contact any of the IPS Affiliate Representatives or

Loris Ramponi

Susan Reynolds Button

Sharon Shanks

 *Either “planetariums” or “planetaria” is an acceptable plural for more than one planetarium. It is style, however, to use the plural “planetariums” in the IPS journal Planetarian.


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