2012-05-11
post/22823110881
photo 04:18:47
The Lunar Ranging Retroreflector, as placed on the Moon by Apollo 15:
The Laser Ranging Retroreflector experiment has produced many important measurements. These include an improved knowledge of the Moon’s orbit and the rate at which the Moon is receding from Earth (currently 3.8 centimeters per year) and of variations in the rotation of the Moon. These variations in rotation are related to the distribution of mass inside the Moon and imply the existence of a small core, with a radius of less than 350 kilometers.
