Double Anniversary of Astronomy in Bern

25-26 November 2022

The Astronomical Institute of the University of Bern (AIUB), Switzerland, celebrated a double anniversary on 25-26 November 2022: 200 years for the «Alte Sternwarte Bern (Uraniae)» (old observatory) and 100 years for the AIUB.

Today, the AIUB has a leading role at international level in fundamental astronomy, in satellite geodesy and in space debris detection and monitoring. This international profile is based on a long tradition of work in celestial mechanics, astrometry and geodesy in Bern. In 1822 the observatory Uraniae was built at the same place as the building of exact sciences hosting the Astronomical Institute today. The position of the observatory’s meridian circle defined the origin of the Swiss Federal Surveying (Dufour map).

In 1922 the Muesmatt Observatory was built and inaugurated on 25 November 1922 as the Astronomical Institute of the University of Bern. The Uraniae became famous due to Rudolf Wolf’s discovery of the 11-year sunspot cycle and due to Georg Sidler’s establishment of the tradition of celestial mechan- ics, in particular of orbit determination, in Bern. The director of the Muesmatt Observatory and founder of the AIUB, Sigmund Mauderli, established international relations with many famous astronomers thanks to his membership of the International Astronomical Union (IAU) and as member of the Governing Board of the Astronomische Gesellschaft (AG). His successor, Max Schürer, built the Zimmerwald Observatory, which was used by Paul Wild mainly for the supernova search program originally inspired by Fritz Zwicky at Caltech and for optical observations of artificial Earth satellites. Later on, the Zimmerwald observatory became one of the first satellite laser ranging (SLR) stations. In recent years, the observatory was enlarged by several domes to become the largest observatory worldwide dedicated to the optical observation of space debris.

The centennial jubilee of the institute and the bicentennial jubilee of the old observatory motivated the two-day celebration end of November 2022 in Bern with a ceremonial act, a scientific symposium and activities and presentations for a broad audience. In addition, a “Festschrift” on the history of astronomy and geodesy in Bern has been published.

‘‘the Zimmerwald observatory became one of the first satellite laser ranging (SLR) stations.’’

The scientific symposium, which was attended by about 200 guests and participants, included presentations by Claude Nicollier, former Swiss astronaut and professor at EPFL (École Polytechnique Federal Lausanne), Tim Flohrer, head of the Space Debris Office at ESA, and Markus Rothacher, president of the Swiss Geodetic Commission and professor at ETHZ (Eidgenössische Technische Hochschule Zürich).

The presentations and video recordings are available at: https://www.aiub.unibe.ch/about_us/news__ events/double_anniversary/index_eng.html

The AIUB has an international reputation in satellite geodesy. The well-known Bernese GNSS Software is a pillar of its work enabling applications to high–precision orbit determination of artificial Earth orbiting objects. The software is today used by almost 800 institutions worldwide for research and, by federal or national agencies, for the establishment of first-order networks. The applications are manifold, comprising, e.g., the estimation of time-variable gravity fields based on GRACE/GRACE-FO data, which is highly relevant for climatological research. For decades AIUB has been heavily involved in many international collaborations and projects, most of them under the umbrella of the International Association of Geodesy (IAG). The institute also has a leading role in the field of the optical observation of space debris. The Swiss Optical Ground Station and Geodynamics Observatory in Zimmerwald (near Bern) is the world’s largest observatory in terms of the number of telescopes for the optical detection of space debris. Characterisation and cataloguing of space debris are important activities at AIUB, as well. The Zimmerwald observatory is also one of the most productive sites worldwide for satellite laser ranging thanks to its highly automated mode of operation.

The Astronomical Institute has a long history of collaborating with COSPAR. Prof. em. Gerhard Beutler was deeply involved in the Commission for coordination of Space Techniques for geodesy and Geodynamics (CSTG), a joint commission of the IAG, the IAU, and COSPAR (now sub-commission B2 of COSPAR). He also served as chair of CSTG’s Technical Panel on Satellite Dynamics (PSD). Dr. Heike Peter has served as vice-chair of the Panel, as well, and Prof. Adrian Jäggi is currently its vice-chair. Prof. Thomas Schildknecht has been serving as vice-chair and subsequently as chair of the Panel on Potentially Environmentally Detrimental Activities in Space (PEDAS).

‘‘The institute also has a leading role in the field of the optical observation of space debris.’’