‘100 Hours of Astronomy’ Celebrating 100 Years of the Planetarium

2-5 October 2025, the International Astronomical Union Office for Astronomy Outreach (IAU OAO) and the International Planetarium Society (IPS), two of the world’s leading organisations dedicated to public engagement with astronomy, will team up to celebrate the 100th anniversary of the first planetarium. To mark the occasion, the organisations will deliver a 100-hour marathon of astronomy events and activities taking place across the world.

100 Hours of Astronomy event is run annually by the IAU OAO to encourage people from all over the world. This year, the IAU OAO partnered with IPS to highlight the legacy and importance of planetariums for fostering our sense of global togetherness and curiosity in the wonders of our Universe.

Read more about the marathon and advartise your event on the OAO Astronomy Engagement Events Calendar!

Photo: IAU OAO