Figure 2
Images of actual lunar regolith samples returned from Apollo missions (a,b), manufactured lunar simulant OPRL2NS with added iron nanoparticles (c,d), and iron powders FE100 and FE325 (e,f). (a) Lunar regolith: Thin film section showing metallic iron (Fe0) at the surface of the grain12, 22. (b) Lunar regolith: Closeup SEM view of sample 10,084 showing metallic Fe mounds of 20 Å to 1 \(\upmu\)m diameters (NASA Photo S87-38846). It is believed that these iron particles resulted from vapor deposition during micro-meteoroid impacts11. (c) Lunar simulant: OPRL2NS, magnification: ×10,000. (d) Lunar simulant: OPRL2NS, magnification: ×20,000. Both images of OPRL2NS show 25 nm spherical iron nanoparticles dispersed across the surface of underlying base simulant. (e) Iron powder: FE325, superfine pure iron powder, particle size < 45 μm. Particles are mostly spherical. Magnification: ×8000. (f) Iron powder: FE100, fine pure iron powder, particle size < 150 μm. Particles are irregular, not spherical. Magnification: ×8000.
