Lunar degree 2 potential Love number determination from satellite tracking data

Abstract

The lunar potential Love number k ₂ has been determined using available satellite tracking data coming from the Lunar Orbiters I-V, the Apollo 15 and 16 subsatellites, Clementine and Lunar Prospector. Some SMART-1 spacecraft tracking data are also included. A previous determination using spacecraft data reported k ₂ = 0.026 +/- 0.003 (ten times the formal error), whereas lunar laser ranging results report lower values, around k ₂ = 0.0210 +/- 0.0025. The best estimate obtained here results in k ₂ = 0.0213 +/- 0.0075 (ten times the formal error as well), closer in agreement with the lunar laser ranging values.