The planetary scientist has one great wish

Christoph Mordasini deals with the formation and evolution of planets inside and outside our solar system. In an interview he explains why the University of Bern has been at the forefront of space research since an experiment on the moon. And he reveals the question to which he would very much like to have an answer.

Buzz Aldrin entrollt anlässlich der ersten Landung auf dem Mond am 21. Juli 1969 das Sonnenwindsegel der Universität Bern. © NASA, Apollo Image Archive
When the second man, Buzz Aldrin, stepped out of the lunar module on July 21, 1969, the first thing he did was to unfurl the Bernese solar wind sail and plant it into the ground on the moon, even before the American flag. © NASA, Apollo Image Archive

«uniaktuell»: uniaktuell: The University of Bern can look back on a 50-year success story in space research. One first highlight was the Solar Wind Composition experiment on the moon. How important do you think this early success was for the University of Bern, Mr. Mordasini?
Christoph Mordasini: This early success was very important because valuable contacts could be established at that time, including with NASA, which still work today. For example, we from the University of Bern regularly go to the NASA "Jet Propulsion Laboratory", where the satellites and space probes for large space missions are built and controlled. Being there is extremely important for us space researchers. I can tell you something personal from my time as a physics student at the University of Bern. Of course it was great for me to attend lectures and tutorials by luminaries like Hans Balsiger, Kathrin Altwegg or Fritz Bühler. Photos of Fritz Bühler exist, where you can see him explaining the solar wind sail, which was to be erected on the moon, to a delegation of close-cropped NASA astronauts in Bern. This is living history as it were, which really moves me.

Besuch einer NASA-Astronauten-Delegation am Physikalischen Institut der Uni Bern. © Bild: Universität Bern
Visit of a NASA astronaut delegation at the Physics Institute of the University of Bern. © Image: University of Bern
Fritz Bühler (stehend links) und Daniel Germann (sitzend) vom Berner Sonnenwindsegel-Team erklären den Apollo-13-Astronauten Fred Haise, John Swigart und James Lovell die Konstruktion des Sonnenwindsegels. © Bild: Universität Bern
Fritz Bühler (standing left) and Daniel Germann (sitting) from the Bernese solar wind sail team explain the construction of the solar wind sail to Apollo 13 astronauts Fred Haise, John Swigart and James Lovell. © Image: University of Bern

And where does Bern stand today in space research?
It is fair to say that the University of Bern occupies a leading international position in space research. In the beginning, the focus at the Physics Institute in Bern was mainly on the construction of instruments and experiments for space missions, whereas today we are more diverse and contribute a lot to theoretical research and observations. For example, we are at the forefront of exoplanetary research, i.e. the exploration of planets outside our solar system. One of the tools used for this is CHEOPS, the space telescope developed and built at the University of Bern under the leadership of Willy Benz.

Das Berner Weltraumteleskop CHEOPS (CHaracterising ExOPlanet Satellite) untersucht Planeten in fremden Sonnensystemen. Dabei ist die Schweiz zum ersten Mal, zusammen mit der ESA, für eine ganze Mission verantwortlich – unter der Leitung der Universität Bern. © ESA/ATG Media Lab
The Bernese space telescope CHEOPS (CHaracterising ExOPlanet Satellite) investigates exoplanets. This is the first time that Switzerland, together with ESA, is responsible for an entire mission - under the leadership of the University of Berne. © ESA/ATG Media Lab

We are also the "Leading House" for the National Centre of Competence in Research PlanetS. This definitely has a wide reach, which we notice on very different occasions. Recently, for example, we advertised a doctoral position at PlanetS. We received 50 excellent applications from all over the world, which is an extremely high response for our field and shows how internationally renowned space research is in Bern.

You studied astrophysics at the University of Bern and then went abroad – among others to the renowned Max Planck Institute. Why did you return to the University of Bern in 2015?
For someone who works in planetary physics, there are very few places in the world that offer similar opportunities as the University of Bern. With the National Centre of Competence in Research PlanetS, participation in international space missions or the Center for Space and Habitability CSH, we have a very international environment in Bern. This was already the case when I was a student. But now there is even more exchange, top-class experts come to Bern and give lectures; this personal access to the elite of space research is extremely valuable. And here in Bern, of course, the working conditions are extremely good, and we have many international students, especially at doctoral level and postdocs. The University of Bern offers good career opportunities. I supervise Bachelor and Masters students myself, which is very important to me, after all I used to be one myself (laughs). The astrophysics of extrasolar planets is a very young field of research, a great deal has not been explored and studied yet. This gives me the opportunity to provide the students with seminal topics that have not been broadly researched yet, with topics on the front lines, and not just with exercises to keep them occupied. Thanks to national and international networking, I can also send them to colleagues abroad or to the other NCCR institutes in Switzerland. This is very satisfying for both sides.

The renowned scientific journal Nature has just published a study on the possible discovery of an exposed exoplanet core. You led the theoretical interpretation of this discovery.
Yes, it really is fantastic. An exposed core of an exoplanet could be observed for the very first time ever. We in Bern were asked to interpret the observation theoretically using our "Bern Model of Planet Formation and Evolution". Statements can be made about how a planet was formed and how it has evolved using this model. We have been continuously developing the Bern model since 2003. Insights into the manifold processes involved in the formation and evolution of planets are integrated into it. These are, for example, submodels of accretion, i.e. the growth of a planet's core, or how planets interact gravitationally and influence each other. Processes in the protoplanetary disks in which planets are formed, which we include in the model, are also important in planet evolution. The model is also used to create so-called population syntheses, which show which planets develop under certain conditions in a protoplanetary disk.

Which open questions in your field of research do you hope will be answered in the future?
I would be extremely interested to know how many planets there really are and what properties they have, i.e. how many Earth-like planets there are, how many giant planets, where they are and where they occur, whether they are alone, in pairs or with many. In short: I would simply very much like to have a complete picture. But of course I would also like to understand why this is the case. But that is a very big wish (laughs). And if I may be utopian: I would, of course, love to be able to get into a spaceship and fly to a star formation region where planets are being formed at the moment. If we could see up close how planets are formed and not just from a distance of hundreds of light years, that would of course be incredibly fascinating and would advance our understanding of physical processes enormously. But that's science fiction. Even if science fiction has often been caught up by reality, I don't believe in traveling at superlight speed, and so the distances even to the nearest star formation region are very long. For example, the star formation region closest to us in the constellation of Taurus is 450 light years away. Although it is not impossible to get there, for example for an unmanned probe, it would simply take a very, very long time.

Bernese space exploration: With the world’s elite since the first moon landing

When the second man, "Buzz" Aldrin, stepped out of the lunar module on July 21, 1969, the first thing he did was to unfurl the Bernese solar wind sail and plant it into the ground on the moon, even before the American flag. This Solar Wind Composition experiment (SWC) which was planned and analyzed by Prof. Dr. Johannes Geiss and his team from the Physics Institute of the University of Bern was the first great highlight in the history of Bernese space exploration.

Bernese space exploration has been working with the world’s elite since then. The resulting numbers are impressive: Instruments have flown into the upper atmosphere and ionosphere with rockets 25 times (1967-1993), 9 times into the stratosphere on balloon flights (1991-2008), over 30 instruments have flown on space probes, and with CHEOPS the University of Bern is sharing responsibility with the ESA for a whole mission.

The successful work of the Department of Space Research and Planetary Sciences (WP) from the University of Bern Physics Institute was consolidated by the foundation of a university competence center, the Center for Space and Habitability (CSH). The Swiss National Fund also awarded the University of Bern the national research focus (NFS) PlanetS, which it manages together with the University of Geneva.

About Christoph Mordasini

Christoph Mordasini has been a lecturer at the University of Bern Physics Institute since 2015. After studying physics at the University of Bern and specializing in astrophysics, he spent six years in Germany at the Max Planck Institute for Astronomy as Alexander von Humboldt and Reimar Lüst fellow. His main research focuses are the theory of the formation and evolution of planets, which he investigates using analytical and numerical models, and the comparison of theory and observation. In addition to theoretical work, he is involved in various projects on detecting and characterizing extrasolar planets. He has already spent over a hundred nights observing at the giant telescopes in Chile.


PD Dr. Christoph Mordasini
Physics Institute, Space Research and Planetary Sciences (WP)
Direct line: +41 31 631 51 58

Media Release

First exposed planetary core discovered

Researchers led by the University of Warwick have discovered the first exposed core of an exoplanet, which provides an unprecedented glimpse inside the interior of a planet. Christoph Mordasini from the University of Bern is leading the theoretical interpretation of this discovery.

About the author

Brigit Bucher is Head of Media Relations and the “Space” representative at the University of Bern Communication & Marketing Department.