The European Southern Observatory (ESO) research facilities

“I have always loved ESO”

Prof. Willy Benz
Photo: © Alessandro Della Bella

The European Southern Observatory (European Southern Observatory, ESO) is the leading European organisation for astronomical research. Having built some of the world’s largest and most technologically advanced telescopes at various sites in the Atacama Desert in Chile, ESO is able to conduct advanced astronomical research. The meetings of the ESO Council are currently chaired by Willy Benz, who is the Director of the National Centre of Competence in Research ‘PlanetS’ and Professor of physics and astrophysics at the University of Bern.

Why is it important for Switzerland to be a member of the European Southern Observatory (ESO)?
Prof. Willy Benz: Modern astronomy requires the use of increasingly complex and therefore increasingly expensive telescopes and instruments. Switzerland's participation in ESO provides Swiss astronomers with access to facilities and resources that they would not otherwise have access to and thus enables them to conduct research that would not otherwise be possible. The international pooling of resources creates new opportunities even for countries much larger than us, such as Germany or France, which are also members of ESO.

Finally, from a purely practical standpoint, there are not many clear nights per year in Switzerland, so our astronomers are always looking for sites like the Atacama Desert in Chile, where the sky offers a maximum number of nights a year for observations. The southern sky is also richer than the northern sky because we can see the heart of our galaxy!

What challenges will ESO face over the next few years?
The Extremely Large Telescope (ELT): a 39-metre diameter telescope is something that has never been done before! In addition, the design chosen is more complex than what we find in today's telescopes: the quality of optics and imaging is unprecedented. It is really a technological, industrial (the largest dome in existence) and financial challenge (the project is equivalent to 6-7 times ESO's annual budget). At the same time, the challenge is also to build the ELT while maintaining all of ESO’s other facilities, particularly the Very Large Telescope (VLT), and state-of-the-art astronomical instruments to best serve the European community.

What scientific breakthroughs will be made possible with the ELT?
In my area of expertise, exoplanets, the ELT will finally allow us to observe these bodies directly. The larger the telescope mirror, the greater the resolution, and the more we will be able to distinguish between the light coming from a planet and the light coming from its star. This in turn will enable us to identify the chemical composition of the atmosphere of the planet in question, the climatic conditions, the temperature at ground level, and whether the latter allows water to exist in a liquid state.

The first image of a supermassive black hole was presented in April. ESO contributed to construction and operations of the Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Pathfinder Experiment (APEX), two of the eight ground-based radio telescopes that made this revolutionary observation possible.
Photo: ESO

What benefits does Switzerland derive from its financial contributions to ESO, particularly with regard to construction of the ELT?
ESO member states pay an annual contribution that allows their researchers to have access to ESO-operated telescopes and instruments by way of a competitive system based on telescope time slots. In addition, scientists and engineers from ESO member states can join consortia involved in the development and production of the instruments that enable telescopes to do science. In exchange for their efforts, consortia receive guaranteed observation time in much greater quantities than would otherwise be possible. In particular, the demand for the ELT will be huge. By having Swiss astronomers take part in the construction of two instruments, the Mid-infrared ELT Imager and Spectrograph (METIS) and the High Resolution Spectrograph (HIRES), Switzerland secures significant observation time for its research community.

What tasks do you have to perform as chair of the ESO Council and how much of your time is devoted to them?
It is important to set boundaries, because you cannot devote yourself entirely to this position even if you would like to. I’d say that the workload takes up about 30% of my time on average with considerable fluctuations.

I have always loved ESO. I have been involved in ESO activities in one way or another ever since my first observation mission to Chile back in 1982 and I have served on several committees. For me, ESO is a remarkable organisation that has retained the same lustre over the past 50 years and has held onto its position as the world's leading organisation for ground-based astronomy. Thanks to its facilities, ESO has secured European predominance in the field of astronomy.

Chairing the ESO Council allows you to play a more active role within the organisation. You are part of the action, have a say in decisions, have a voice. For me it is an incredible opportunity to be part of this, especially at a time when the world's largest telescope is being built.

How do you reconcile research, teaching and family life?
It has not always been easy and the days have been long. There are things that you stop doing. For example, I used to be director of the Physics Institute at the University of Bern and was involved in various committees, I stopped all of this. As for the family: my children are grown up, so I no longer have as many constraints as I did when I was young. When they were younger at home, this would not have been possible. But now I'm making the most of it.

What did you feel when you chaired your first meeting of the ESO Council in Switzerland in March 2019? What did that moment represent for you?
Hosting the ESO Council meeting in Switzerland was a way of demonstrating that our country assumes its full role within the organisation and assumes its responsibilities at all levels. We are a reliable partner that ESO can depend on. At the same time, Switzerland depends on the organisation to enable its astronomers to be leaders in this field. As this is only the second time in its history that the ESO Council has met in Switzerland, I remember feeling rather proud as I told myself that the Swiss delegation to the Council had done a really good job!

To what extent can astronomy benefit society?
Astronomy has several virtues. First, it helps to improve our knowledge in general by allowing us to place Earth within its context. What is the origin of the universe, the solar system and Earth in particular? Are there other planets similar to ours with life forms of their own? These questions have always been topical in the history of humanity. However, thanks to technological progress, we may actually become the first generation to answer these questions scientifically! In another field, but also at the forefront of our current knowledge, ESO has helped to make it possible to produce the first image of a supermassive black hole in the heart of the Messier 87 galaxy.

Astronomy is also a science that interests the general public and young people in particular. It encourages people to study natural sciences. While not everyone will study astronomy, some may become engineers, physicists, biologists, computer scientists, or work in similar fields. This succession is important, because an educated population advances the overall level of society, enabling it to better face tomorrow’s challenges.
Finally, astronomy contributes to technological innovation. For example, to answer the question of whether there is life elsewhere in the universe, new machines are being built that push technology beyond its comfort zone. This fuels the engine of technological innovation and progress. It is not construction of a telescope or instrument per se that drives industry, but rather the technologies developed to enable this construction. Very often such technologies are later used in other areas, including more commercial ones that can have a direct impact on society.