A word from the ISSI executive Director

Dear friends of ISSI,
Dear visitors of our web page,

The ISSI web page has been renovated recently thanks to Andrea Fischer and Saliba Saliba. ISSI is proud to present itself to the interested reader with a fresher look but keeping the organization of the website clearly structured and familiar so that interested users can find what they need easily and quickly.

I hope you and your loved ones are safe in this time of crisis! As many others, ISSI and its activities have been hit by the pandemic, but fortunately, no staff member has become ill. We have turned to teleworking as of March 17th and will remain so at least until the end of the eastern recess. But the ISSI office can be reached by phone and mail will be checked daily thanks to the presence of at least one ISSI staff on duty. The easiest way to reach us these days, though, is by email.

ISSI teams and workshops up to mid-May have been postponed. We will be watching the situation and adjust as it will evolve. Decisions about postponements have and will be taken together with the team leaders and the conveners at least six weeks prior to the scheduled event. As of today, there are no postponements of decisions on proposals and applications submitted to ISSI.

We all hope that the damage to the ISSI program can be kept to a minimum; we will resume as soon as the situation and the authorities will allow. ISSI will step-up its activities after the crisis to allow postponed meetings to occur as soon as possible.

In the meantime, our thoughts and sympathies are with those all over the world hit by COVID 19!

Stay safe and hope to meet you all in person at ISSI sometime soon!

Tilman Spohn

ISSI executive Director

Job Posting: ISSI Director (full-time)

The International Space Science Institute (ISSI) in Bern, Switzerland, invites applications for a full-time position of


starting August 1, 2021. The appointee will be a member of the Directorate of ISSI whose recognized scientific stature ensures the visibility and keeps the high scientific standards of the Institute. The current Directorate is composed of the Executive Director, Prof. Tilman Spohn, the Director of the Earth Observation Program, Dr. Anny Cazenave, the Director of the Solar and Plasma Program, Prof. Rudolf von Steiger; and the Director for Astrophysics and Cosmology, Prof. Joachim Wambsganss. The directors are inspiring and managing ISSI’s activities in their scientific fields: workshops, forums, international teams, working groups the institute’s guest scientist program.


Complete Job Posting >>

Obituary Prof. Johannes Geiss (1926-2020)













It is with great sadness that we must bid farewell to our founding father and honorary director

Prof. Johannes Geiss (1926-2020)

Johannes Geiss died on January 30, 2020 at the advanced age of 93. In him, we have lost a great scientist and supporter of the sciences forever.

Johannes Geiss was born on September 4, 1926 in Stolp in what was then Western Pomerania as the son of an estate manager. How different the world must have looked in that time, when his grandfather had the horse hitched to the cart every two days in order to travel to the barber in the neighboring village for a shave; not fifty years later, his grandson landed an experiment on the Moon.

During the war years, Johannes Geiss was able to attend Gymnasium (high school), which he left in 1944 with a Notabitur (early school-leaving qualification in wartime) in order to immediately start a physics degree in Göttingen. Even then, his lecturers must have been struck by the young student’s rapid comprehension and irrepressible need to communication, and he was thus employed as a teaching and research assistant even during his studies. In 1950, he obtained a degree in physics from Max von Laue, and he obtained his doctorate from Wolfgang Paul in 1953. The latter he referred to, with the greatest respect, as the real part of the equally well-known but more flamboyant Wolfgang Pauli, who worked at the ETH at the time; Geiss loved such wordplays which reveal themselves to mathematical initiates.

During his time in Göttingen, Johannes Geiss also met his wife, Carmen, with whom he shared a deep partnership all his life.

His first position as a physicist brought Johannes Geiss to Fritz Houtermans’ institute at the University of Bern. Houtermans wanted to apply mass spectrometry, with which Geiss had successfully been able to determine the isotopic composition of lead, to determine the age of meteoric matter. So, at the beginning of the fifties, his glass mass spectrometer with him, he went to Bern, which would become the new center of his life, and by 1974 he was a naturalized citizen of Switzerland.

Johannes Geiss brought a breath of fresh air to an institute which was perhaps a little outdated at the time and soon found enthusiastic companions to establish a group which would quickly make a name for itself in astrophysics. Periods spent abroad in Chicago with Harold Urey and as a young professor in Miami broadened and rounded out his education; in between, he habilitated in experimental physics, in particular extraterrestrial physics, at the University of Bern in 1957. He was appointed as an associate professor in 1960, and as a full professor in 1964. At the beginning of the sixties, he had to take over management of the institute for the increasingly ill Houtermans, and was thus appointed director of the institute following Houtermans’ death in 1966; a position which he held until his retirement in 1990. In 1970/71, he also served as dean of the Faculty of Science, and in 1982/83 he served as rector of the university.

But Johannes Geiss was pulled to other places time and again in order to maintain and develop his ever-growing network. He spent the year before the first landing mission to the Moon – Apollo 11 – at NASA in Houston in order to lobby for the ingeniously simple solar wind sail developed by him and his group. The solar wind would be captured with an aluminum foil during the astronauts’ time on the surface of the Moon as the solar wind arrives there unhindered because of the Moon’s lack of an atmosphere and a magnetic field. The simplicity of the experiment and the excellent reputation of the Bernese mass spectrometer made him perfect for the job. But it took great tenacity, coupled with the previously mentioned enthusiasm and the necessary bit of luck for the sail, which weighed scarcely a pound, to fly with Apollo 11 in July 1969 and then a further four times. Its analysis, in particular the ratio of the helium isotopes captured, corresponded to a measurement of the average density of the universe as a whole – a ground-breaking result for which he, together with Hubert Reeves, was awarded the Einstein Medal by the Albert Einstein Society in Bern in 2001.

Johannes Geiss made clever use of his growing reputation in order to continue improving the conditions in Bern and to make the institute one of the top names in astrophysics and keep it that way. Under his leadership, the mass spectrometer was made so much smaller that it could be flown on space probes. At the same time, he was able to realize the necessary laboratories and a top-notch clean room in Bern for the tests and calibration. Bern thus became an internationally sought-after partner for space missions, a role which it still retains today thanks to the tireless efforts of Johannes Geiss and his successors. Of the many missions which Johannes Geiss was involved in as principal investigator or as co-investigator, the solar wind ion composition spectrometer stands out as a prime example. Developed with his friend George Gloeckler, this instrument orbited the sun on the Ulysses space probe for almost two decades on a polar orbit. This experiment achieved (among many other results) a refinement of the isotopic signature of helium measured with the solar wind sail. It is hard to find a better illustration of his progressive, unceasing spirit of research.

Even after his retirement, Johannes Geiss’ drive diminished not one jot. He still mustered all of his enthusiasm and convinced those in charge of the European Space Agency ESA and the Swiss Space Center to establish a new institute which would focus on the interdisciplinary analysis, evaluation and interpretation of the results of space missions. The International Space Science Institute was thus born almost exactly 25 years ago. In the first eight years, he served as its executive director and made the institute a center where scientists from all around the world come together in an informal and interdisciplinary setting in order to reach for new scientific horizons. Thanks to his vision, the ISSI has today become a place of meeting and exchange for thousands of space scientists.

Johannes Geiss’ work was internationally recognized with many distinguished honors. He didn’t like the often stiff atmosphere of such events, greatly preferring informal discussions with colleagues, students and anyone at all, when it came to science or any other topic which sparked his enormously broad and active interest. However, some of these honors filled him with a certain amount of pride – and deservedly so: His appointment as a Foreign Associate of the National Academy of Sciences of the USA (1978), his honorary doctorate from the University of Chicago (1986), the aforementioned Einstein Medal (2001) and the Bowie Medal, the highest honor of the American Geophysical Union (2005).

Johannes Geiss passed away in his sleep on January 30, 2020 surrounded by his loved ones. He leaves behind his wife Carmen and his daughter Jana, with her family. His legacy will continue to shine at the Physics Institute at the University of Bern and at the International Space Science Institute.

Bern, February 6, 2020
Rudolf von Steiger

Dr. Anny Cazenave, ISSI Earth Science Director, Receives the 2020 Vetlesen Prize for her Pioneering Work in Charting Modern Sea Level Change

Dr. Anny Cazenave is to receive the most prestigious Vetlesen Prize 2020 for Achievements in the Earth Sciences.

The Vetlesen Prize is designed to be equivalent to the Nobel prize and will be administered at a ceremony at Colombia University this spring. Cazenave, a geodesist by training,  will be honored for pioneering the use of space satellite data to measure the topography and the rise of the surface of the oceans, together with related changes in ice sheets, glaciers, ocean temperature and land water storage. Her work has linked the sea level rise with climate change.

Sea level rise is seen as one of the most important and threatening consequences of climate change. Two thirds of the sea level rise is now understood as coming from the melting of land ice as a direct consequence of global warming and one third from the expansion of ocean water. That ratio was only half to half when Cazenave started her work.

As director of ISSI’s Earth Science Program Anny Cazenave has supervised the program and has organized a significant number of workshops related to global change. ISSI is proud to have her on the scientific staff.

The Vetlesen Prize is awarded every three years for “scientific achievement resulting in a clearer understanding of the Earth, its history, or its relation to the universe”. The prize was established in 1955 by George Unger Vetlesen, a Norwegian born sailor, naval engineer and shipbuilder in the United States.


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Applications now open for Alpbach Summer School 2020

Comparative Plasma Physics in the Universe (Alpbach Summer School 14-23 July 2020)

Would you like to use engineering and/or science to solve problems that can be addressed by space missions? If yes, consider applying to the Summer School Alpbach.

This year, sixty European engineering and science students will be selected to participate in the 44th edition of the Summer School Alpbach. Participants will be engaged in an in-depth learning experience, attending stimulating lectures on relevant aspects of space science and engineering, and working intensely within four groups to define and design a space mission under the supervision of noted scientific and engineering experts.

The topic of the Summer School Alpbach 2020 is Comparative Plasma Physics in the Universe and will focus on different scales observed at Earth, Planets, Sun, Across the Universe.

Application Deadline March 31, 2020

What to expect:
• 10 day learning experience, attending lectures and working intensely within groups to defi ne and design a space
mission under the supervision of experts 

• formulate observational objectives to advance the understanding of the behaviour and the coupling processes of plasma at several astrophysical scales (Earth, Planets, Sun, Across the Universe)
• Presentation of a mission study to an expert review panel on the last day

More details: www.summerschoolalpbach.at