Commentary: The IAU and its evolution

In 2019 the International Astronomical Union (IAU) celebrated its 100th anniversary, which provided an opportunity to not only look back but also think about the future role of scientific unions. Founded in 1919 shortly after World War I, the IAU was one of the first of its kind for any scientific field, with a mission to foster relations between astronomers of different countries and promote the study of astronomy. Most of the IAU’s early work focused on science diplomacy and the organization of scientific symposia. The IAU has also served—as it does today—as the internationally recognized authority for assigning official names and designations to celestial bodies and the surface features on them.

A century later, the world, the science, and the IAU have changed dramatically. Progress in astronomical research has surged because of crucial technological advancements, increasingly powerful telescopes and satellites, more sophisticated software and computing, and most of all, international collaboration. One hundred years ago humankind knew of only eight planets—all in our own solar system—and of only one galaxy, our own Milky Way. Today it is clear that the universe is teeming with billions of galaxies and planets and that the bulk of it consists of mysterious dark matter and dark energy. We may also be the first generation of humans with the technology to answer one of the biggest questions: Are we alone in the universe?

The IAU has grown to 85 member countries and more than 12 000 individual members—professional astronomers with PhDs—of more than 100 nationalities. In the last decade, the IAU has developed from an organization focused primarily on astronomical research to one that is firmly engaged with society. As president of the IAU for the past three years, I had the honor of leading this venerable organization into its second century.

The IAU has provided a platform to bring together scientists of many ages and backgrounds from around the world. I remember well my own first IAU General Assembly in 1979, when my partner, astronomer Tim de Zeeuw, and I traveled from the Netherlands and camped in Montreal. I was an MSc student in theoretical chemistry at the time, and it was a fantastic experience to hear high-level presentations and talk to famous astronomers like Subrahmanyan Chandrasekhar.

The low-threshold and inclusive nature of our general assemblies and symposia has been a key characteristic throughout the more than 400 IAU-organized meetings over the past century; a significant fraction of the IAU’s annual expenditure goes toward enabling the participation of young scientists and astronomers from developing nations. The IAU receives the bulk of its funding from the annual contributions of its member countries, with some additional strategic funding provided in partnerships.

As highlighted in its 2020–30 Strategic Plan , the IAU now has four offices that focus on (1) training the next generation of astronomers , (2) communicating and engaging with the general public , (3) furthering astronomy as a tool for nations’ development and capacity building , and (4) bringing astronomy to schools to excite children about STEM.

That evolution of the IAU was triggered by the 2009 United Nations (UN) International Year of Astronomy (IYA2009), which commemorated the 400th anniversary of the first time Galileo turned a telescope to the sky. IYA2009 was the world’s largest science event in decades, engaging several hundred million people in nearly 150 countries and setting an example for other International Year celebrations. One consequence of IYA2009 was the IAU’s strategic plan “Astronomy for the Developing World ,” which led to the establishment of the Office of Astronomy for Development in Cape Town, South Africa, in 2011.

A decade later, the IAU’s 100th anniversary presented an opportunity to revitalize such activities and celebrate a century of astronomical discoveries. The IAU100 theme “Under One Sky” emphasized the global nature of our science and the role that the IAU has played in bringing people together. IAU100 hosted more than 5000 activities that engaged more than 100 million people in 143 countries.

Highlights included the flagship conference “Astronomy with and for Society” in Brussels and an open-source exhibition, “Above and Beyond ,” developed to showcase the fascinating past century of astronomy and presented in 75 countries. The project with the greatest worldwide impact was “Name ExoWorlds ,” which gave all countries the opportunity to organize national campaigns to name a star and an exoplanet. Its aim was to make people think about our place in the universe and to instill a sense of cosmic citizenship. A special highlight was the celebration of the centenary of the 1919 solar eclipse that confirmed Einstein’s general relativity theory.

Inclusivity was embedded in all projects, most notably in “Women and Girls in Astronomy ” activities, the “Inspiring Stars ” exhibition for visually impaired people, and a 2019 IAU symposium dedicated to equity, diversity, and inclusion. That event led to a Springboard to Action document with recommendations for how individuals, national members, and national organizations could make improvements, ranging from having an equity, diversity, and inclusion session at all conferences to making structural changes that promote diversity.

The IAU100 Final Report reviews those highlights and more. The November 2020 edition of the Communicating Astronomy with the Public (CAP) journal summarizes best practices and lessons learned relevant for other organizations and educators organizing large-scale events, such as starting several years in advance, establishing clear themes, and making any related materials freely available. The network of more than 120 active national outreach coordinators that was grown as part of IAU100 was crucial to its success and forms one of the lasting outcomes of the event.

IAU100 ended just as countries worldwide were starting to lock down to contain the COVID-19 pandemic. The IAU community reacted quickly. Engineers helped design and manufacture ventilators, and astronomers used supercomputers to model the structure of the virus and its spread. The IAU shared new and existing educational projects including webinar training workshops for educators, online lectures and tutoring, and physical distribution of “astronomy in a box” toolkits to reach populations with little or no internet access. Astronomy also lifted some people’s spirits during the stressful times, with projects that included (socially distanced) stargazing, art inspired by astronomy, and video essays.

Scientific meetings moved online and enabled young researchers and many more astronomers from around the world to join and present their work at almost no cost. However, most IAU-sponsored symposia were postponed until they could be in-person meetings, which offer unstructured discussions that have social benefits and can trigger new ideas and collaborations. The IAU 2021 General Assembly, to be held in Busan, South Korea, was moved to 2022 and will have a hybrid online and in-person format. How well such hybrid meetings work and whether they will become the new normal is yet to be explored.

Around the same time that COVID hit, another major challenge to our field became apparent: protecting the dark and radio-quiet skies. Our skies are now being threatened not just by huge increases in urban lighting and radio interference from telecommunications, but notably by the launch of swarms of what are known as small satellite constellations. Those developments have a major effect not only on astronomical observations, but also on human health, wildlife, and the fundamental right of every human to view and access the night sky. Even amateur astronomers struggle to take a picture without satellite streaks, such as those shown below.

The IAU and its partners organized an online workshop about the issue that drew 950 participants, many more than would have been at an in-person meeting, including a significant fraction of non-astronomers. The workshop resulted in a report that describes the impact of human activities and makes recommendations for mitigating actions. An executive summary was presented to the UN Committee on the Peaceful Uses of Outer Space. The IAU subsequently issued a call to establish a new Centre for the Protection of the Dark Sky from Satellite Constellation Interference to coordinate internationally against that new threat to astronomy.

Exploring the wonders of the universe and viewing the starry night sky are opportunities available to anyone, anywhere in the world. As the IAU embarks on its second century, more and more data from powerful telescopes are open and accessible to all. The IAU is therefore starting workshops in developing countries to train young astronomers in the use of those data.

Overall, astronomy will continue its unique and diverse role within society, from offering exciting science, inspiration, perspective, and a sense of connection to stimulating education, technology development, and capacity building. With its four offices, the IAU has put in place the organizational structure to attain those goals. But concerted efforts by many volunteers and funding will be necessary to maintain and further develop its regional and global networks. To quote the Indian philosopher Rabindranath Tagore: “You can’t cross the sea merely by standing and staring at the water.” I am confident that the IAU community will cross these many seas by working together.

Ewine van Dishoeck is a professor of molecular astrophysics at Leiden University in the Netherlands. She served as the IAU president from 2018 to August 2021.