Lunar Levitation Dust Instrument for a Lander: Investigating Electrostatic Dust Transport on the Moon

Kurzfassung

Dust levitation on the lunar surface, first observed by Surveyor 6 as horizon glow at the terminator, remains a significant challenge in understanding electrostatic dust transport mechanisms. The study of lunar dust is critical due to its potential hazards for surface operations, including optical degradation of scientific instruments, lunar based astronomy, increased wear on mechanical components, and risks to astronaut health. Furthermore, understanding dust dynamics is essential for the success of future lunar exploration missions, including the Artemis program and the establishment of long-term lunar bases. This research presents the theoretical framework, instrument development, and initial experimental validation of a dedicated lunar dust levitation detection system designed for deployment on a lunar lander. The instrument utilizes a 532 nm pulsed laser in conjunction with a stereo camera system to detect and characterize levitated dust particles within distances of up to 10 m. The targeted particle size range extends from 1 to 20 µm, with the potential to detect larger particles. The theoretical framework incorporates electrostatic charging, which is mainly by local plasma environment, photoemission of electrons due to solar Ultraviolet (UV) and X-rays, and lofting mechanismsas well as particle dynamics to model the size distribution and motion of dust in the Moon’s near-surface plasma environment. The generated electrostatic surface potential accelerate dust particles of certian size which are then lofted above the surface and launched into sheat the region with upward velocity, as described in the dynamic fountain model of lunar dust. Following to the work, we calculate the maximum height (Zmax) reached by dust particles of micron range (1-10 µm) and the exit velocity at the top of the sheath (Vexit) for the cases of fast and slow solar streams. It is observed that only under fast solar streams the particles gain the required electrostatic potential to escape the sheath.