Asteroid-meteorite connection: Regolith effects implied by lunar reflectance spectra

The effect of soil formation on the spectral characteristics of asteroids were estimated in situ properties of materials affected by the space environment other than those associated with agglutinates. In his initial survey of the reflectance properties of lunar samples, J.B. Adams measured a few chips from the exterior and interior of Apollo rocks. For Apollo 12 basalts 12053-12063 , the exterior and interior spectra exhibited strong absorption bands which were very similar in nature; the exterior fragment was a bit brighter, which was attributed to microbrecciation. Mature lunar soils measured undisturbed surface areas at the landing sites. It was hypothesized that freshly exposed material at fresh impact craters should be comparable to powdered rock samples in the laboratory. This expected trend seemed to be true with the early reflectance data, but as the more complete near-infrared data has become available it is clear that there is no simple correspondence of rock type (laboratory powder or chip measurement) to freshly exposed surface material (telescopic measurements of fresh crater classes).