The physics of the Earth's space environment is dominated by the interaction between the solar wind and the terrestrial magnetic field. The structures that are created in this interaction are: the bow shock, in which the supersonic solar wind is decelerated; a transition layer called the magnetosheath; the magnetopause, which is the boundary of the magnetosphere and the magnetotail where the Earth's magnetic field is dominating. In principle these structures are all magnetoplasmas, i.e., electrically charged particles (ions and electrons), and electric and magnetic fields dominate the physical processes.

The aurora is the visual evidence for the interaction between the Earth's magnetic field and the solar wind and the resulting dynamics in the Earth's magnetosphere. In the auroral region electrons collide with the particles in the high atmosphere which then emit electromagnetic waves, partially at optical wavelengths. Further measurable effects are the changes in magnetic field strength at the Earth's surface, which are caused by the ring current in the magnetosphere. The understanding of the solar-terrestrial relationship, often called space weather (mpeg, 4.1 MB), is a research area that is rapidly gaining importance as geostationary satellites, communication systems, as well as energy distribution networks in the polar regions can be endangered by increased solar wind energy input into the Earth's magnetosphere.

The institute is involved in many current (Cluster, Double Star, THEMIS) and future projects such as RBSP, MMS and Resonance.