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How do magnetic fields influence plasmas in interstellar and interplanetary space?

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How scientists use lasers to learn about the universe — plasma Learn about the PHELIX (Petawatt High-Energy Laser for Heavy Ion Experiments) laser at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. PHELIX is used for plasma and atomic physics research.

Magnetic fields play a fundamental role in shaping the behavior of plasmas throughout interstellar and interplanetary space, despite their relatively low absolute strengths. Because plasmas consist of charged particles, their motion is intrinsically linked to electromagnetic forces.12

In interplanetary space, the solar wind—a collisionless plasma—carries an extension of the Sun’s magnetic field, which is effectively "frozen" into the conducting fluid. When this plasma encounters a planet like Earth, the magnetic field acts as a barrier, creating a magnetosphere that deflects the solar wind around the planet via a bow shock.34

Magnetic fields also facilitate complex energy transfers. Through a process called reconnection, magnetic fields from the Sun can link with a planet's magnetosphere, storing vast amounts of energy that may be released during geomagnetic substorms. Furthermore, magnetic field lines can trap energetic particles in regions like the Van Allen radiation belts and accelerate electrons to create phenomena such as the aurora. On a larger scale, these fields are essential to nearly all astrophysical phenomena, influencing the distribution of cosmic rays and the dynamics of interstellar media.431