Question

apollo astronaut stepped on the moon have kept some large mirrors their collect information about how the distance to the moon is measured using these

Answer 1

The ongoing Lunar Laser Ranging experiment measures the distancebetween surfaces of Earth and the Moon using laser ranging. ... Laser light pulses are transmitted and reflected back to Earth, and the round-trip duration ismeasured.

Answer 2

Apollo astronauts have kept large mirrors to collect information about the distance to the moon, this ongoing project is known as the Lunar Laser Ranging experiment.

This basically measures the distance between the surfaces of earth and the moon. This is done using laser ranging techniques.

During the Apollo Program retroreflectors were planted on the moon. The laser light pulses are transmitted back to the earth.