What is Lunar-laser-ranging-experiment?

The Lunar Laser Ranging Experiment involves bouncing laser beams off retroreflectors placed on the Moon's surface during the Apollo missions and by the Soviet Lunokhod rovers. By measuring the time it takes for the laser light to travel to the Moon and back, scientists can determine the distance between the Earth and the Moon with high precision. This experiment provides valuable data for testing theories of gravity, studying the Moon's orbit, and understanding fundamental aspects of astrophysics. It also helps improve our knowledge of the Earth-Moon system's dynamics.