European Space Weather Week 2025

Charge exchange of solar wind protons precipitating on lunar regolith and the effect on the near lunar plasma environment

Not scheduled

20m

Tonsalen

Poster CD7 - Space weather at unmagnetized or weakly magnetized solar system objects CD7 - Space weather at unmagnetized or weakly magnetized solar system objects

Speakers

Gabriella Stenberg Wieser (Swedish Institute of Space Physics) Martin Wieser (Swedish Institute of Space Physics)

Description

Solar wind protons precipitating onto the lunar regolith is partially backscattered to space and leads to sputtering of surface materials. Particles emitted to space have a charge state distribution determined by the lunar regolith and independent of the precipitating particle. Recent measurements on the lunar surface by the NILS instrument[1] on Chang’e-6 and the ASAN instrument[2] on Chang’e-4, both combined with Artemis data[3]  allow to investigate the full charge state distribution of emitted hydrogen energies above 10s of eV. We explore the fate of the emitted particle populations in the near lunar environment and the formation of lunar exosphere layers.

[1] R. Canu-Blot, et al. (2025), The Negative Ions at the Lunar Surface (NILS) Instrument on the Chang’E-6 Mission. Space Science Reviews, doi:10.1007/s11214-025-01162-w

[2] M. Wieser, et al. (2020), The Advanced Small Analyzer for Neutrals (ASAN) on the Chang’E-4 Rover Yutu-2. Space Science Reviews, doi:10.1007/s11214-020-00691-w

[3] C. Lue, et al.,(2018), Artemis observations of solar wind proton scattering off the lunar surface. Journal of Geophysical Research: Space Physics, doi:10.1029/2018JA025486