"There are devices left behind by the astronauts that can be “seen” by some telescopes. These are corner reflectors that reflect light back in the direction it came from. Some specialised observatories regularly illuminate these with laser beams and view the reflected signal in telescopes. With the reflected signal the distance of the Moon can be tracked to a few millimetres accuracy. Australian scientists first carried out lunar laser ranging in 1977." Source: https://maas.museum/observations/2007/05/30/can-we-see-neil-armstrongs-footprint-or-was-the-moon-landing-a-hoax/