The Moon’s surface slopes and slope-distributions from the Lunar Orbiter Laser Altimeter

The Lunar Reconnaissance Orbiter (LRO) successfully entered orbit around the moon on June 23, 2009. Since then, the Moon’s topography has been sampled with unprecedented detail and coverage by the Lunar Orbiter Laser Altimeter (LOLA). Surface slopes are computed from comparison of measurements among the five illuminated spots on the surface from each laser shot, as well as across multiple shots along the ground profile. Slopes and slope distributions for the sampled areas are obtained, and preliminary properties of the lunar surface roughness over the range of length-scales from 10’s m to km’s will be presented. We focus on notable properties of the distribution computed locally of median and RMS slopes, correlation length, and Hurst exponent (relatable to the power spectral slope). Regional slope histograms are considered for characteristic terrain types such as mare plains, impacts basins, and the highlands. The high precision and high density of LOLA measurements allow a quantitative morphologic characterization of the lunar surface pertinent to studies of surface processes and evolution, as well as for possible future landing site selection.