Solar Wind & Magnetospheres

Solar wind shaping the magnetosphere of Venus (top), Earth (middle), and Mars (bottom, © ESA).

The Sun is constantly emitting charged particles, the so-called solar wind, which carries the solar coronal magnetic field to the outer parts of our solar system. Although the solar wind is constantly present, it is variable in strength, as the Sun periodically ejects more mass during active than during quiet periods. When the supersonic solar wind impinges upon obstacles throughout the solar system, such as magnetic fields or charged particle atmospheres of planets, moons, and comets, it dynamically forms bow shocks ahead of these obstacles and engulfs the obstacles that thereby become magnetospheres. The magnetospheres evolve differently at each solar system body, as they are of different size and type, e.g., due to the presence (or not) and strength of a body-intrinsic magnetic field.

Of particular interest to us are basic physics of gases of charged particles (plasmas) and solar wind-magnetosphere interactions, for instance, plasma and magnetic flux transport in the magnetotail, interaction of shock-reflected particles with the solar wind, wave propagation and amplification on magnetospheric boundaries and in the magnetosphere, and connections between these and other phenomena. To study the interaction of the solar wind with the Earth's and other magnetospheric environments in the solar system (different planetary and cometary magnetospheres), in-situ measurements at those different environments and, more specifically, at different regions within the magnetospheres are needed.

Members of the Space Plasma Physics group are actively involved in analyzing in-situ data from multiple spacecraft missions, including Cluster, THEMIS, MMS, GEO-KOMPSAT-2A, and Rosetta. They are also preparing future measurements at Mercury (BepiColombo, launched in 2018) and participating in future missions to Mars (Chinese Mars Mission) and to a comet or an extrasolar object (Comet Interceptor). A new class of remote sensing observations of the Earth’s outer magnetospheric boundary and polar lights will become available by SMILE.