Comparing Rocket Exhaust Effects across Lunar Landing Sites Using LRO Narrow Angle Camera images

Abstract

High-resolution Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) images are used to study the effects of rocket exhaust on lunar soil reflectance properties at the Apollo, Luna, Surveyor, and Chang’e 3 landing sites. Areas disturbed by rocket exhaust appear as photometric anomalies in NAC images and are preserved owing to the lack of weathering processes on the Moon. Destruction of fine-scale surface structure, smoothing of the surface, and/or redistribution of fine particles created high-reflectance areas around the landers that we refer to as blast zones. Reflectance profile shapes are consistent across all landing sites and reflectance changes are similar in magnitude (12-16% increase) across all sites, indicating that these lunar surface features are not erased on the order of decades. Blast zone area scales exponentially with lander mass and thrust, although variations arise owing to differences in engine configuration and descent trajectories.