Do the retroreflectors left on the moon reflect sunlight visible in the United States?

Question

My grandkids have doubts about the validity about the Apollo missions, and having told them about the retroreflectors and proving it with a visit to a local planetarium. I got to thinking that if the reflector will reflect a laser beam, Will it relect sunlight? If so, how do you calculate the time of reflection?

Answer 1

A retroreflector is a cubic section - that is, one corner of a cube. The device left on the moon by Apollo 11 in 1969 is a roughly 2-ft square array of 100 of these corner-cube reflectors. Physically, it will only reflect a beam of light straight back at its source (well, parallel to it, at least).

As such, it would only reflect sunlight directly back at the sun. Except for phenomenally rare circumstances, you would never see it from here.

It might be possible, if you stood precisely on the Earth's day/night terminator line as a lunar eclipse was occurring, that you would see a brilliant flash just as the edge of the Earth's shadow crossed over one of the reflector arrays. Provided that you were standing within a few miles of the exact line between the reflector and the sun.

Like I said, phenomenally rare circumstances - but still conceivable.

Answer 2

No, the retroreflector will only reflect light back in the direction it came. It is an array of corner reflectors, arranged much like the reflectors in car and bike tail lights but optically much better.

http://en.wikipedia.org/wiki/Corner_reflector

Tell your grand children this - it's true. If the Apollo astronauts had not landed on the Moon, scientists and engineers outside the USA would have seen that the Apollo program was a fake immediately. NASA could not hide the fact that the radio signals were not coming from the Moon if the missions had been faked, because it it well known around the world how to build highly directional radio antennas.

You can be sure that the Russians tracked the Apollo spacecraft by radar and by radio transmissions during their flights and there is a very good chance several other countries did as well.

If the Apollo astronauts took off but merely orbited the Earth, their spacecraft would have been seen by naked eye observation from the ground unless the orbit was very high. In that case the spacecraft could have been seen with ordinary binoculars or small telescopes. In any case the spacecraft could have been tracked by radar. If the Russians had detected a hoax they would have kept quiet about it for 38 years?

The conspiracy nonsense largely rests on the implicit assumption that there were no scientists or engineers outside the USA at the time, which is obviously wrong.

You should also look at the "bad astronomy" site

http://www.badastronomy.com/bad/tv/foxapollo.html

Answer 3

Sorry, but as other posters have said, a retroreflector reflects light back to the source.

Also, by the time it gets back to the Earth, the light is *very*very* weak, because it has spread out so much. Even under good viewing conditions, only a single reflected photon is received every few seconds. (Some ground stations have been improved to get about 100 photons per 15 nanosecond pulse.) Here is a picture of a laser beam from the McDonald Observatory being sent to the Moon.

Answer 4

A retro-reflector reflects light back to it's source.
If you were between the sun and the device you may get a reflection,but we can't be in that position on earth.
A laser beam must travel over 400,000 miles so it would have to be very powerful,also the angle is so small that it would require a pulsed laser that could spray the area to get a return.
Like shooting at a target with a machine gun.

Answer 5

Yes, they can reflect sunlight; but they are oriented to reflect light coming from the Earth, not from the Sun. You must also considr that the moon always shows the same face to the Earth.

Hence the chance to see sunlight reflected on them is very low; comparable to the chance of seeing a moon eclipse. I cannot give a hint on when this could happen without accurate data on position and orientation of the reflectors!

Answer 6

well the reflectors are designed to reflect a laser beam from the earth back to the earth. So it is likely that the sunlight hits the reflectors and bounces off at an angle that doesn't make it to earth.