Exploring the Lunar Laser Ranging Experiment

[r.vittalkiran]

Why did they land on the other side of the Moon?
And how did they place the Laser reflector (http://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment) on the front side of the Moon?

 

[Integral]

According to this http://www.ilovestars.com/Moon/moonlanding.html" , all landings have been on the near side.

Leaving the reflector was easy, they just put it down and walked away.

 

[russ_watters]

Welcome to PF.

All of the lunar landing sites are on the near side of the moon. http://en.wikipedia.org/wiki/File:ApolloLandings.jpg

 

[r.vittalkiran]

The picture clearly shows that they landed on the other side of the Moon...
Can anyone answer me properly?

 

[russ_watters]

Um, no, as the picture was taken from earth, it shows we landed on the near-side of the moon. Find yourself another picture to verify it from (I actually compared it to a picture of the moon I took to make sure).

Where are you getting this wrong idea from? This idea is not hard to debunk with 30 seconds of googling (which is how Integral and I got our information). You really should be making more of an effort here.

 

[r.vittalkiran]

And how to you take the snap of moon?
Even i wanted to do the same>
Check This> https://www.physicsforums.com/showthread.php?t=393638

 

[r.vittalkiran]

so... if they had landed on near side of the moon, why couldn't we see them? for that matter, nevertheless we should have seen their wagons.
see them waving the flag? lol

 

[davenn]

so... if they had landed on near side of the moon, why couldn't we see them? for that matter, nevertheless we should have seen their wagons.
see them waving the flag? lol

you maybe could if you had an extremely powerful optical telescope ! maybe if the Hubble space telescope exsited back then, maybe it may just pick out a bump of the lander but its doubtful!
Just think ... if they had landed on the far side then we would never have seen the pix or video or any other radio comms from them ! If you remember ... if you are old enough... prob not, since you are even asking/these questions ... as the Apollo command/service module orbited the moon, they always went into radio blackout as they went around the far side

Dave

 

[davenn]

The picture clearly shows that they landed on the other side of the Moon...
Can anyone answer me properly?

as the others said ... not true

the pic on that wiki page clearly shows the near side of the moon. I can't even begin to understand how you could think it is the far side ? you can even go out on a full moon night and look up and see the same thing as in that pic

2 pix below the one from your wiki link and one I took with my camera, see the simularity ? :) ... its the same :)

Dave

 

[K^2]

so... if they had landed on near side of the moon, why couldn't we see them?

From 300,000km away, in order to see something 1 yard across, you'd need a telescope with a lens/mirror roughly 160m in size. That's a telescope significantly larger than a football field just in diameter.

There is absolutely nothing even close to that here on Earth. We do not have a telescope large enough to see the lander, let alone flags or even rovers.

The only pictures of the landers taken not by the Apollo astronauts have been by recent Lunar orbiter satellites. And even on these, the lander looks like a spot of dirt on the picture.

 

[Pengwuino]

There seems to be a misconception brought about because of the ability for satellites to take very detailed pictures of the Earth from orbit. The Moon is FAR away. Those satellites looking down on us are quite low! The way to do it would be to use a massive telescope on the ground, but the atmosphere has an effect on your image. If my back of the envelope calculation is right, unless adaptive optics are used, your best resolution from a ground based observatory is something like 2km. Although, adaptive optics are used... so I guess that's a moot point.

 

[K^2]

You might be able to score an order of magnitude from adaptive optics. I doubt it'd be much better than that. Besides, you still run into optical resolution limits, which are no better.

Now, if you had information about the phase of the signal, like we do with radio telescopes, that would be different. We'd be able to build an optical telescope with effective diameter equal to that of the Earth. You'd be able to look at dust grains on the Moon with that. But for that we need "electronics" that operate at optical frequencies. Maybe with optical computers we'll finally have that in a decade or two.

Astronomy will become a very different subject practically over night when the first arrays go online. We should be able to actually map out some nearby exoplanets with that. Can't wait to see it.

 

[pallidin]

To my understanding, though we never landed on the "far" side of the moon, we did in fact orbit around the moon many times prior to landings. Many photos taken.