Southeastern Section–55th Annual Meeting (23–24 March 2006)

Paper No. 8
Presentation Time: 10:40 AM


LIU, Yang1, THOMPSON, James R.2, TAYLOR, Lawrence A.3 and PARK, Jaesung1, (1)Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, (2)ORNL&Deptartment of Physics, University of Tennessee, Knoxville, TN 37996, (3)Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996-1410,

Lunar dust, the <20 μm portion of the Moon's regolith, posed several unanticipated problems during the Apollo Missions. With our plans for returning humans to the Moon, it is paramount to address these situations. For example, an embarrassing problem involved the fact that none of the '$M rock boxes' built at Oak Ridge National Labs remained sealed at the vacuum of the Moon – i.e., they all leaked exposing the lunar samples to terrestrial air - because of the ubiquitous dust. Dust caused problems with astronauts' breathing, upon their return to the Lunar Module – is this dust toxic to humans? The extreme abrasiveness of the lunar soil and dust impaired movement of joints in tools and instruments, as well as on astronaut's suits. It is obvious that the lunar dust problem needs to be mitigated [Taylor et al., 2005, AIAA]. The myriads of nanophase metallic Fe grains (np-Fe0) in the impact glass of agglutinates in the soil present unusual properties, including ferromagnetism, which can be used for dust abatement – e.g., a brush with a magnet attached. Therefore, it is obvious that we must investigate the magnetic properties of this finest portion of the lunar regolith. The <45 μm portion of previously unstudied Apollo17 soil, 70051, was measured using a SQUID (Superconducting Quantum Interference Device) magnetometer. The magnetization curve depicts a strong ferromagnetic component from the np-Fe0 particles. The initial susceptibility of the sample (28 x10-4 emu/gm Oe) is not dissimilar from other lunar soils. The metallic iron (Fe0) content in sample 70051 (~0.77 wt% from saturation magnetization) is within range of other lunar soils (0.1-0.92 wt%). We also measured several lunar soil simulants: The most common lunar regolith simulant, JSC-1, made from a basaltic tuff, as well as our synthesized simulants contain np-Fe0 particles suspended in glass of lunar composition. New insight into the magnetic characteristics of these samples provides insight into possible dust mitigation processes.