The focus of this department is the solar interior, the solar atmosphere, the solar magnetic field, the heliosphere, and the interplanetary medium, as well as solar radiation and solar energetic particles. The balloon-mission Sunrise, a balloon-borne solar observatory, is managed by this department. The mission investigates our central star from a height of about 35 km. In addition to several other participations in space missions, the department significantly contributes to the ESA's Solar Orbiter.

This department investigates the interior, the surfaces, atmospheres, ionospheres, and magnetospheres of planets and their moons, as well as comets and asteroids. The department currently contributes or has contributed to important space missions such as the ESA's missions JUICE to the Jovian system, BepiColombo to Mercury and Rosetta to comet Churyumov-Gerasimenko as well as NASA's missions InSight to Mars and Dawn to the asteroid belt.

Helioseismology and asteroseismology are tools that use the oscillations of the Sun and stars to probe their interior structure and dynamics. This allows us to test and refine the theory of stellar structure and evolution, thereby bringing us closer to understanding solar and stellar magnetism. The department hosts the German Data Center for NASA's Solar Dynamics Observatory, and is preparing to host the data center of ESA's exoplanet hunting mission, PLATO.