Shape and Size Relationship of Several Lunar Dusts: Preliminary Results

Introduction: Before establishing a human outpost on the Moon, numerous problems associated with lunar dust must be addressed and mitigated [1, 2]. The deleterious nature of lunar dusts was experienced during all Apollo missions. Lunar dusts (brought in on dirty spacesuits and boots) contaminated the atmosphere in the lunar module and irritated the eyes, sinuses, and throats of the astronauts [1, 2]. In contrast to short exposure times during the Apollo missions, astronauts partaking in missions of extended presence on the Moon will be subjected to prolonged exposure, if lunar dust contamination is not substantially mitigated. The physiology effects of lunar dusts on humans are being actively studied by a multi-discipline group of scientists, Lunar Airborne Dust Toxicity Analyses Group (LADTAG) (e.g. [3-5]). Lunar dust, < 20 μm fraction of the lunar soil (definition adopted by LADTAG), consists of ~20 wt% of lunar soil [6,7]. Detailed information of the lunar dust properties, chemistry and mineralogy, particle size distribution (PSD), particle shape, magnetic susceptibility, and electrostatic properties, is important for quantitative interpretation of such studies. To achieve this, our group has conducted analyses on chemistry and mineralogy [8, 9], size distribution [10, 11], shape characterization [12] of different lunar soil (<1 mm regolith) and dust (<20 μm soil) samples. We also developed a technique to separate <3 μm fraction of lunar soils from the bulk sample [13,14].