For 24 years, the “Solar System School” has been offering a unique graduate program for doctoral students. Today, the 250th graduate successfully defended her dissertation.

• Milestone: To date, 250 researchers have successfully earned their doctorates through the International Max Planck Research School for Solar System Science.
• Collaboration: The graduate school is a joint project of the Max Planck Institute for Solar System Research, the University of Göttingen, and the Technical University of Braunschweig.
• Research projects: With topics in astrophysics, geosciences, and instrument engineering, the doctoral candidates make a significant contribution to the research output of the three institutions. 
• Jupiter’s moon: In the 250th dissertation, Ilse de Langen calculated magnetic fields and currents in the inaccessible, subsurface ocean of Jupiter’s moon Europa. 

The “Solar System School” is unique. The International Max Planck Research School (IMPRS) for Solar System Science at the University of Göttingen and at TU Braunschweig, thus the full name of the graduate school, offers doctoral candidates the world’s only doctoral program in the field of solar system research. In their research projects, they not only investigate the current state of the Sun, the planets, moons, comets, and asteroids in our Solar System. They also explore how our cosmic home has evolved, as well as how and why it differs from other star systems. In doing so, the young researchers employ a wide variety of methods: they simulate processes on computers, analyze extraterrestrial rock samples in the laboratory, evaluate observational data from ground-based telescopes and space probes, and contribute to the development and construction of space instruments.

The 250th dissertation from the International Max Planck Research School for Solar System Science, which Ilse de Langen successfully defended today, serves, among other things, to prepare for two current Jupiter missions: NASA’s Europa Clipper and ESA’s JUICE (Jupiter Icy Moons Explorer) are currently on route to gas giant and will, among other bodies, also study its moon Europa starting in 2030 and 2031. Its subsurface saltwater ocean makes it a particularly exciting research subject: Conditions there could allow for the emergence of life. However, the ocean is hidden beneath an ice crust at least 20 kilometers thick and is inaccessible to direct measurements. Indirect clues are provided primarily by the magnetic field in the vicinity of Europa.

“Europa ‘lives’ in an extreme magnetic environment,” explains Ilse de Langen. The moon orbits within Jupiter’s magnetic field, which is not only approximately twenty times stronger than Earth’s, but also tilted by nearly ten degrees relative to Europa’s orbit. Since the planet spins around its axis in just under ten hours, Europa experiences a sort of constant magnetic roller coaster ride. The rapidly changing magnetic conditions induce electric currents in Europa’s ocean, which in turn generate a variable magnetic field. The Europa Clipper mission will measure this magnetic field with high precision to infer the characteristics of the ocean.

In her dissertation, Ilse de Langen described these relationships theoretically and simulated them on a computer. Among other things, she found that the dynamic, electromagnetic interaction triggers previously unknown inertial waves in Europe's ocean. Once Europa Clipper and JUICE arrive in the Jovian system, the results will help interpret the magnetic field measurements.

“Doctoral students play an important role in the research activities of the Max Planck Institute for Solar System Research,” says Thorsten Kleine, Managing Director of the Max Planck Institute and spokesperson for the Solar System School. “The Solar System School offers doctoral students a comprehensive overview of the field of solar system research and facilitates interdisciplinary exchange with researchers from related disciplines,” adds Sonja Schuh, coordinator of the Solar System School. It is not uncommon for young scientists to produce outstanding results already in their dissertations, thereby contributing at a very early stage to the international reputation of Göttingen an Braunschweig as scientific and academic centers.

In recent years, doctoral candidates have made significant contributions to the following current research findings, for example:

•  In the early Solar System, the ring-shaped region outside Jupiter’s orbit served as a kind of “incubator” for planetesimals of very different compositions. 
• The Sun’s magnetic field plays a crucial role in maintaining giant, cool plasma structures in the solar corona, known as prominences. 
• The birthplace of the near-Earth asteroid Ryugu, which was sampled by the Japanese space probe Hayabusa 2, is thought to have been located near Jupiter. 
• The violent hurricanes that race across Jupiter in band-like storm bands extend to a depth of 2,000 kilometers. 
• The Sun exhibits oscillations with periods of several months. These oscillations control the Sun’s rotation pattern. 

Within the Solar System School currently about 35 researchers are pursuing their doctorates, 45 percent of whom are women. Each year, approximately 200 students from around the world apply for these highly sought-after doctoral positions.

The Solar System School is a consortium of the following institutions:

• Max Planck Institute for Solar System Research
• Institute for Astrophysics and Geophysics, University of Göttingen
• Geoscience Center, University of Göttingen
• Institute for Numerical and Applied Mathematics, University of Göttingen
• Institute for Geophysics and Extraterrestrial Physics, TU Braunschweig
• Institute for Theoretical Physics, TU Braunschweig
• Institute of Computer and Network Engineering, TU Braunschweig