Electromagnetic particle-in-cell simulations of the solar wind interaction with lunar magnetic anomalies.
We present the first three-dimensional fully kinetic and electromagnetic simulations of the solar wind interaction with lunar crustal magnetic anomalies (LMAs). Using the implicit particle-in-cell code iPic3D, we confirm that LMAs may indeed be strong enough to stand off the solar wind from directly impacting the lunar surface forming a mini-magnetosphere, as suggested by spacecraft observations and theory. In contrast to earlier magnetohydrodynamics and hybrid simulations, the fully kinetic nature of iPic3D allows us to investigate the space charge effects and in particular the electron dynamics dominating the near-surface lunar plasma environment. We describe for the first time the interaction of a dipole model centered just below the lunar surface under plasma conditions such that only the electron population is magnetized. The fully kinetic treatment identifies electromagnetic modes that alter the magnetic field at scales determined by the electron physics. Driven by strong pressure anisotropies, the mini-magnetosphere is unstable over time, leading to only temporal shielding of the surface underneath. Future human exploration as well as lunar science in general therefore hinges on a better understanding of LMAs.
Centre for mathematical Plasma Astrophysics (CmPA), Department of Mathematics, KU Leuven, Celestijnenlaan 200B, bus 2400 B-3001 Leuven, Belgium and Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles à Saint Quentin, 11 Boulevard D'Alembert, 78280 Guyancourt, France.
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J
Deca
Swedish Institute of Space Physics (IRF), SE-751 21 Uppsala, Sweden.
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Divin
Centre for mathematical Plasma Astrophysics (CmPA), Department of Mathematics, KU Leuven, Celestijnenlaan 200B, bus 2400 B-3001 Leuven, Belgium.
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Lapenta
Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles à Saint Quentin, 11 Boulevard D'Alembert, 78280 Guyancourt, France.
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B
Lembège
High Performance Computing and Visualization (HPCViz), KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
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S
Markidis
Laboratory for Atmospheric and Space Physics (LASP), University of Colorado, 1234 Innovation Drive, Boulder, Colorado 80303-7814, USA.
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Horányi