Abstract
Energetic charged particles trapped in planetary radiation belts are hazardous to spacecraft. Planned missions to iron-rich asteroids with possible strong remanent magnetic fields require an assessment of trapped particles energies. Using laboratory measurements of iron meteorites, we estimate the largest possible asteroid magnetic moment. Although weak compared to moments of planetary dynamos, the small body size may yield strong surface fields. We use hybrid simulations to confirm the formation of a magnetosphere with an extended quasi-dipolar region. However, the short length scale of the field implies that energetic particle motion would be nonadiabatic, making existing radiation belt theories not applicable. Our idealized particle simulations demonstrate that chaotic motions lead to particle loss at lower energies than those predicted by adiabatic theory, which may explain the energies of transiently trapped particles observed at Mercury, Ganymede, and Earth. However, even the most magnetized asteroids are unlikely to stably trap hazardous particles.
Original language | English (US) |
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Article number | e2021GL097014 |
Journal | Geophysical Research Letters |
Volume | 49 |
Issue number | 13 |
DOIs | |
State | Published - Jul 16 2022 |
Keywords
- (16) Psyche
- Psyche mission
- asteroid magnetospheres
- chaotic motion
- energetic particles
- hybrid simulations
ASJC Scopus subject areas
- Geophysics
- General Earth and Planetary Sciences