Lasers prove we've been to the moon !

[Accutronitis]

I have always known there is a laser reflector we put on the moon surface but I didn't know it is what's called a "Retroreflector" which can reflect laser light back to it's source from any angle it hits the reflector ! Pretty cool stuff !

They use a 1 GIGAWATT LASER ! I gota get me one of those !

 

[diachi]

Yup, there's a few videos and threads about this IIRC.

They only get a couple photons back at the detector per pulse. Keep in mind that 1GW rating is peak pulse power, very short, high energy pulses. Average power is significantly lower. Still impressive.

 

[Accutronitis]

Yup, there's a few videos and threads about this IIRC.

They only get a couple photons back at the detector per pulse. Keep in mind that 1GW rating is peak pulse power, very short, high energy pulses. Average power is significantly lower. Still impressive.

I'd still be happy with a half a gigawatt continuous laser ! lol

I bet that baby could be seen from the side from miles away !

 

[paul1598419]

IMO, there is far more evidence of our trips to the moon than this reflector. I think it is the YouTube society that has a conspiracy theory that the moon landings were all faked. Total nonsense.

 

[steve001]

I read this a longtime ago on Sam's Laser FAQ. A person owning a 25W yag laser could see naked eye twinkling. This took place in the very early seventies.

 

[diachi]

I read this a longtime ago on Sam's Laser FAQ. A person owning a 25W yag laser could see naked eye twinkling. This took place in the very early seventies.

Can you dig up a link?

Twinkling, as in from reflections off the moon? Doubtful, seeing as the detectors used for these experiments only pick up a couple of photons per pulse and that's with a large telescope (for both the laser and the detector), and more output power.

 

[paul1598419]

I'd like to see that link also. It does seem doubtful.

 

[Lasing Jake Moon]

I'd still be happy with a half a gigawatt continuous laser ! lol

I bet that baby could be seen from the side from miles away !

Is it the greater the power the wider the beam? What would aperture and the divergence be roughly. (being a noob I only have 2 lasers with one being the Arctic 3.5 with a 2x5mm aperture and a max 4.8 mRad divergence.

(see Im starting to sound clever to myself now) Not to you lot though just quoting their website.

 

[paul1598419]

Is it the greater the power the wider the beam? What would aperture and the divergence be roughly. (being a noob I only have 2 lasers with one being the Arctic 3.5 with a 2x5mm aperture and a max 4.8 mRad divergence.

(see Im starting to sound clever to myself now) Not to you lot though just quoting their website.

It is purely hypothetical. None currently exists.

 

[diachi]

It is purely hypothetical. None currently exists.

What's purely hypothetical?

 

[steve001]

Can you dig up a link?

Twinkling, as in from reflections off the moon? Doubtful, seeing as the detectors used for these experiments only pick up a couple of photons per pulse and that's with a large telescope (for both the laser and the detector), and more output power.

I'd like to see that link also. It does seem doubtful.

Look for "visibility of high power laser beams"
https://www.repairfaq.org/sam/laserlia.htm#lialls2<br>
I used to be able to sparkle off the new moon with my YAG at full power and full convergence. It takes some doing but you can see the sparkle from the Sea of Tranquillity with the naked eye off the corner cube reflector, aka: retroreflector left there in 1969 by the astronauts.

 

[diachi]

Look for "visibility of high power laser beams"
https://www.repairfaq.org/sam/laserlia.htm#lialls2<br>
I used to be able to sparkle off the new moon with my YAG at full power and full convergence. It takes some doing but you can see the sparkle from the Sea of Tranquillity with the naked eye off the corner cube reflector, aka: retroreflector left there in 1969 by the astronauts.

Huh, thanks for the link... Still, not sure I believe it. Would need to see it with my own two eyes I think! :beer:

May need to ping Steve a message to see if he can confirm...

 

[steve001]

Huh, thanks for the link... Still, not sure I believe it. Would need to see it with my own two eyes I think! :beer:

May need to ping Steve a message to see if he can confirm...

I first read this way back in the late 90's. I guessing the retroreflector was much cleaner when Steve did it. I think it will be difficult to ping him he may not be living for all I know. Here's a very old thread. https://groups.google.com/forum/m/#!topic/alt.lasers/4xq98LBfTvo

 

[paul1598419]

What's purely hypothetical?

My mistake. I thought they were talking about a gigawatt visible CW laser to point at the moon.

Edit: saw the link from Steve Quest about using a 30 to 57 watt 532nm laser to see it reflected off the mirrors left by the astronauts in 1969 in the Sea of Tranquility on the moon. Can't say that I believe it, though.

 

[Accutronitis]

Can you dig up a link?

Twinkling, as in from reflections off the moon? Doubtful, seeing as the detectors used for these experiments only pick up a couple of photons per pulse and that's with a large telescope (for both the laser and the detector), and more output power.

Your being polite, MUCH MORE POWER, About 40,000,000 time more power ! lol

I first read this way back in the late 90's. I guessing the retroreflector was much cleaner when Steve did it. I think it will be difficult to ping him he may not be living for all I know. Here's a very old thread. https://groups.google.com/forum/m/#!topic/alt.lasers/4xq98LBfTvo

That link took me to a discussion about "Jello laser" ?

My mistake. I thought they were talking about a gigawatt visible CW laser to point at the moon.

Edit: saw the link from Steve Quest about using a 30 to 57 watt 532nm laser to see it reflected off the mirrors left by the astronauts in 1969 in the Sea of Tranquility on the moon. Can't say that I believe it, though.

We were but then steve001 mentioned reading something where a person (who is not here at the moment) had posted at some time in the past that he had hit the "Retroreflector" left on the moon by Apollo Astronauts with a mere 25 watt (the original number) laser and he said (unconfirmed) that he could see with the naked eye "sparkling" on the moon when in the video it took a gigawatt laser pulse and a very large astronomical telescope to detect the very small amount of returning photons of laser light ? Something doesn't past the smell test there IMO but what do I know ?

 

[steve001]

Your being polite, MUCH MORE POWER, About 40,000,000 time more power ! lol

That link took me to a discussion about "Jello laser" ?

We were but then steve001 mentioned reading something where a person (who is not here at the moment) had posted at some time in the past that he had hit the "Retroreflector" left on the moon by Apollo Astronauts with a mere 25 watt (the original number) laser and he said (unconfirmed) that he could see with the naked eye "sparkling" on the moon when in the video it took a gigawatt laser pulse and a very large astronomical telescope to detect the very small amount of returning photons of laser light ? Something doesn't past the smell test there IMO but what do I know ?

You didn't read closely enough. I said I read that from Sam's Laser FAQ 20 some years ago. Thats possibly when he did it but he gives no precise date, could have been earlier. In the intervening decades those mirrors have become dirtier. I have no idea if this was possible decades ago but I see no one replying to Steve questioning his claim in that old thread.