One of my neighbors, who is a retired physics engineer and a former Univ. professor, and I had a conversation about this not too long ago. I asked him why not just point the telescope at Keck observatory on Mauna Kea at the moon at find all the stuff left behind? He said the strongest telescope on earth isn't powerful enough for that task.
However, he did go on to say that the Apollo astronauts did leave what basically are reflector mirrors (I forgot the technical term) on the moon at certain well known coordinates. Three of 'em I believe. Aim any high powered laser or infrared device at the mirrors and it'll bounce the beam back at you. Proving, of course, that someone had to be there to place those things.
Whether this is true or not, I have no clue. Just repeating what I was told.
GO PACKERS!