5. April 2023 | Press releases:

Inaugural lectures by Prof. Dr Jessica Agarwal and Prof. Dr Ferdinand Plaschke Aktivität kleiner Körper im Sonnensystem
Vom Sonnenwind zum Weltraumwetter: Dynamische Prozesse im erdnahen Weltraum

Prof. Dr Jessica Agarwal and Prof. Dr Ferdinand Plaschke, Institute of Geophysics and Extraterrestrial Physics at Technische Universität Braunschweig, will hold their inaugural lectures on

Wednesday, 12 April 2023, at 4 p.m,
Aula, Pockelsstr. 11, Haus der Wissenschaft, 38106 Braunschweig.

Inaugural Lecture “Aktivität kleiner Körper im Sonnensystem” (Activity of Small Bodies in the Solar System)
by Prof. Dr Jessica Agarwal

The small bodies of our solar system, such as asteroids and comet nuclei, are often thought of as samples of the material from which the planets were formed. Compared to the planets, the small bodies are similar to the planetesimals of the early solar system. However, small bodies are also constantly subject to collisions, orbital changes, irradiation by cosmic particles, solar wind and sunlight, and the resulting thermal and dynamic changes.

One particular consequence of such processes is the emission of gaseous and solid material (dust) into interplanetary space. This so-called activity of asteroids and comets is not only observable with space probes, but also accessible to telescopes on Earth or in near-Earth space.

In this lecture, Professor Jessica Agarwal gives an overview of how we can draw conclusions about the nature of their near-surface layers and the processes of change taking place there from measurements of the activity of comets and asteroids.

About the person
Jessica Agarwal studied physics at the University of Jena and at the Free University of Berlin. In 2007, she completed her doctorate at the University of Heidelberg and then conducted research as a postdoctoral researcher at ESA/ESTEC in Noordwijk (Netherlands) until 2010. She then worked as a postdoctoral researcher first at the University of Potsdam and since 2012 at the Max Planck Institute for Solar System Research in Göttingen. Since 2018, she has led a junior research group there funded by an ERC Starting Grant. In 2020, she was awarded a Volkswagen Foundation-funded Lichtenberg Professorship at the Institute of Geophysics and Extraterrestrial Physics at TU Braunschweig.

Inaugural Lecture “Vom Sonnenwind zum Weltraumwetter: Dynamische Prozesse im erdnahen Weltraum” (From Solar Wind to Space Weather: Dynamic Processes in Near-Earth Space)
by Prof. Dr Ferdinand Plaschke

The Earth’s magnetic field does not simply extend into empty space. Rather, it is compressed on the day side facing the sun by the constantly flowing solar wind – a gas of electrically charged particles – and stretched out on the night side facing away from the sun; this is where the so-called geomagnetic tail is formed. The solar wind cannot directly enter the region of the Earth’s dominant magnetic field, the magnetosphere. Instead, the magnetosphere or its outer boundary layer, the so-called magnetopause, acts as an obstacle for the solar wind, which must flow around it. Due to the high speed of the solar wind, the flow around it can only be made possible if a bow shock wave forms in front of the actual obstacle, at which the solar wind is decelerated, compressed and heated up. Thus, due to the interaction of the solar wind with the Earth’s magnetic field, the near-Earth space breaks down into a series of regions with different properties, which are related to each other via the exchange of particles and energy.

Decisive for the dynamics of the system is the interplanetary magnetic field, which is brought to the magnetosphere by the solar wind. Under certain conditions, the process of magnetic reconnection can lead to the unification of the magnetic fields. This allows solar wind particles to enter the magnetosphere via the geomagnetic tail. This produces the auroras typical of stormy space weather; variations in the radiation belts are also the result. The interplanetary magnetic field also leads to further structuring of the bow shock wave and its adjacent regions, the so-called foreshock and magnetosheath regions. Resulting small-scale phenomena and their global impact on the entire magnetospheric system are currently the focus of research.

In this lecture, Professor Ferdinand Plaschke gives an overview of the structure and dynamics of near-Earth space. In particular, he looks at how observations by multi-satellite missions help to understand physics on different spatial and temporal scales.

About the person
Ferdinand Plaschke studied physics and received his doctorate from TU Braunschweig in 2011. He then worked as an assistant researcher at the University of California Los Angeles until the end of 2012. From 2013, he was a junior scientist and researcher at the Space Research Institute of the Austrian Academy of Sciences and temporarily also at the Karl Franzens University in Graz. He regularly taught courses as an external lecturer at TU Graz and FH Wiener Neustadt. In 2021, he completed his habilitation at TU Graz in the field of space physics. Since October 2021, Ferdinand Plaschke has been a professor at the Institute of Geophysics and Extraterrestrial Physics at TU Braunschweig.