Sponsored by the International Planetarium Society, the International Day of Planetariums – formerly known as the International Day of Planetaria – is a day set aside each year to inform the public about what planetariums are and why they exist.

The International Day of Planetariums is celebrated annually on the second Sunday in March. Since being organized in Italy in 1991, the IDP has spread to countries around the world.

The International Day of Planetariums is celebrated annually on the second Sunday in March. Since being organized in Italy in 1991, the IDP has spread to countries around the world.

Why are planetariums important? In today’s light-polluted world, many people have lost touch with the stars. One 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.