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Post by ka9q on Jul 7, 2011 6:04:41 GMT -4
and you'll find Dr. Christian of NASA not only mentioning that stars can be seen from the lunar surface providing one appropriately screens the sun, but additionally, Dr. Christian mentions how wonderfully bright stars, visible stars, appear in space. Indeed, and many astronauts have commented on seeing those stars from the night side of the earth or moon when they turn down the cabin lighting or shield their eyes from it and permit their eyes to dark adapt. See, for example, the book and documentary "In The Shadow Of The Moon", the title of which was taken directly from an interview with one of the Apollo astronauts. I think we can agree that those very same stars that are so easily seen at night are still there with equal brightness during dayside passes and in cislunar space and can potentially be seen by eye if the proper (and time consuming) steps are taken to dark-adapt the eye and rigorously block all stray sunlight and cabin lights during the viewing. And we can agree that those stars can also be seen during the daytime by instruments (such as the HST, or the A16 UV surface camera) that provide their own shielding against stray sunlight, assuming the proper exposures are used. And you've already conceded that stars are much too faint to register on photographs exposed for daytime illumination. So what's left to discuss? Surely you, a medical doctor with a presumably good understanding of human physiology, will not now seriously argue that stars ought to be readily visible to a NON dark-adapted human eye simultaneously viewing a sunlit surface, most likely through a gold filter designed to reflect or absorb most of the light hitting it? What IS your point?!
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Post by fattydash on Jul 7, 2011 6:20:20 GMT -4
I am aware of that. If you were to look in more detail, you would find visibility would be iffy with the ruby reds. The argon lasers used for the Surveyor experiment were weak, 1 watt. but they operated in a spectral range more visibility friendly than the ruby reds. The light from the argon lasers was seen by the surveyor 7 camera with a magnitude roughly that of Sirius. This is per the original report. I found the report on the experiment with the details regarding visibility in the Apogee book on surveyor, in the text and on the disk.
The ruby red lasers employed, one at Lick, on 07/20/1969 and thereafter, were much more powerful than the 1 watt argon lasers of the 1968 surveyor 7 experiment. So for the sake of arguement, let's say the ruby reds were at least as visible as the argon lasers since you have brought up the point. Why didn't the astronauts see the lasers from the surface of the moon? They began operating immediately. Journalists were at Lick prepared to announce that Tranquility Base had been found. Why was there no returned light from the reflector if Armstrong/Aldrin really did set it down at 07/21/1969 02:39 UTC plus a few? Why didn't they see the lasers firing from the CM vantage? If surveyor got a shot of the argon lasers at roughly Sirius' magnitute, and these ruby reds were wattage wise way more powerful, and if you would favor this ruby red light as being visible with respect to the physiology of the astronauts under the circumstances, why was the light never seen? The lasers operated day after day once the reflector was set down.
Ditto for all of the other Apollo trips. If the lasers were visible, why was the light not seen, not photographed?
And again, why was Tranquility base so hard to find on 07/20/1969. If NASA tracked things so well, why did they not know where exactly the Eagle was on the surface of the moon on that night and why did it take so long afterwards to make a reasonably precise determination of the location of Tranquility Base? Why was the reflector for the laser experiment not found by the Lick Observatory team until August?
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Post by ka9q on Jul 7, 2011 6:26:51 GMT -4
These were astronauts who were doing daytime tasks While being constantly reminded by Houston that they were falling behind on a very busy EVA timeline. And while knowing that they only had so much oxygen, water, lithium hydroxide and battery power in their PLSS backpacks, and that they couldn't simply remove their helmets for fresh air if those consumables ran out. And while knowing that the experiments they were setting up and the samples they were documenting and collecting were the culmination of years of work by scientists who were depending on them for the success of that work. And while knowing that they would never get another chance like this (and for Apollo 17, that no one else would either, for a very long time.) Given all that, it really strains credulity that anyone could actually expect such a person to waste the time and effort to see the very same stars that he could see from home, or perhaps from a later earth orbital mission.
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Post by trebor on Jul 7, 2011 6:31:43 GMT -4
And again, why was Tranquility base so hard to find on 07/20/1969. If NASA tracked things so well, why did they not know where exactly the Eagle was on the surface of the moon on that night and why did it take so long afterwards to make a reasonably precise determination of the location of Tranquility Base? Are you not aware Apollo 11 landed off course by quite a considerable distance? There are a few reasons why that was, perhaps you ought to do some research and not rely on the posters here to do it for you.
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Post by fattydash on Jul 7, 2011 6:34:05 GMT -4
With all due respect ka9q, we have been over this. Your point is a good one and accepted in a sense. I agree the astronauts have better things to do than view stars. It is the way they discount the stars altogether, as though they were not even casually accessable. It is one thing to say one is busy doing something more important, it is another thing to say astronauts did not for the most part see any stars for essentially the entirety of the cislunar journey(up to the solar corona viewing episode) when it is well recogniozed there were times when the cabin was dark, when it did not rotate, when stars were allegedly being sought in the context of navigating, when Aldrin himself says in interviews that there wasn't much to do en route to the moon. They kind of sat around if one were to take his account at face value.
I would imagine Armstrong would have said something like, "yeah I saw them and I wasn't impressed". But denying them so robustly, that is not credible.
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Post by fattydash on Jul 7, 2011 6:35:59 GMT -4
I know that trebor. It was a leading question. Go on please. The other questions asked in that post, go on.
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Post by ka9q on Jul 7, 2011 6:39:36 GMT -4
I could answer all those questions, but a) you'd learn more finding the answers for yourself and b) I seriously wonder if it would do any good. I learned a long time ago that hoax believers don't use questions as tools to get answers. They use questions as weapons.
That said, I could make a few suggestions to steer you in the right direction if you really are seriously interested in the answers.
My main suggestion is "do the numbers". That is, compute the apparent brightness of the earthbound laser at lunar distance. Would it even be visible? How would it compare to the brightness of the earth?
Some other questions to ponder: How big was the laser spot at the moon? (Hint: this will depend on the diameter of the transmitting telescope.)
How many trials would have to be conducted to methodically search the entire Apollo 11 "landing ellipse"? How long would they take?
How quickly would the CM fly through that spot at its known orbital velocity assuming it was pointed somewhere along its track? Would it even be visible?
As for the determination of the Apollo 11 landing site, that is best answered by reading the mission reports. The shape of the moon's gravity field was not precisely known in 1969. Indeed it is only now being accurately determined thanks to long-term tracking of various lunar orbiting spacecraft sent there in recent years, particularly the Japanese Kaguya spacecraft that carried a separate relay spacecraft specifically to enable real-time tracking of the main spacecraft while it was on the far side.
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Post by ka9q on Jul 7, 2011 6:48:20 GMT -4
If you were to accurately quote the responses given by the astronauts to that question you would note that they refer specifically to their inability to see stars without the aid of the spacecraft optics.
Michael Collins was CMP (Command Module Pilot) for Apollo 11. One of the CMP's chief duties was navigation, and one of the Apollo navigator's tasks was to realign the inertial reference platform with respect to the stars. That's exactly why they had optics. Since realignments were conducted quite regularly, almost obsessively, including during translunar and transearth coast when the spacecraft was in continuous sunlight, it is quite reasonable to conclude that Collins could see at least his navigation stars through the spacecraft optics. So did Armstrong and/or Aldrin in the LM.
The Apollo guidance computers had a catalog of several dozen navigation stars. Since only one star is as bright as Sirius, they obviously had to use some that were dimmer. They were all generally 2nd magnitude or brighter.
So now we've established that they could see stars even in the daytime as long as they used the optics to exclude stray sunlight -- otherwise they probably wouldn't have gotten home. There are indeed many references to these star sightings in the mission transcripts.
So, I ask yet again...what's your point, exactly? Do you even have one?
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Post by fattydash on Jul 7, 2011 6:59:13 GMT -4
Actually ka9q, I have Donald Beatie's "Taking Science to the Moon" and have studied it well. I also have thoroughly studied the original articles in Nature and Science magazines about the laser ranger experiments. I have been to Lick Observatory nearby my home and investigated the particulars of that eveing and I know how and when the determination of Tranquility Base's location was made and why it took so long.
I am not gaming anyone, I assume you guys all know this stuff. I am trying to get a feel for how you interpret it. How it settles out for you differently than it does for me. I can think of one way the astronauts might have been able to determine their location there on the moon and inform the people at Lick of that. But if I blurt out my idea, it might influence your own take on what or what not was possible that evening given the circumstances.
So I am not asking leading questions to be coy, I know for the most part we are familiar with many of the same facts and I wish to know how it is your side arrives at a different conclusion from me.
I am not so identified with the perspective of Apollo as fraud that I could not change my views. That said, I have been at this for a while and am comfortable with how I see this generally.
Also, there are many things of which I am quite ignorant. well I know more than the guy in the street, but on another thread , someone asked me about radiation issues and I do not know that well enough to participate in an exchange with him/her that would be beneficial to either of us, and I will say that if such is the case.
The visibility stuff, the physiology, the lasers, and so on, I know this stuff inside and out. I presume you do as well. we draw different conclusions from the same basic facts. when I ask a leading question, the reader knows that I am looking for a chain of reasoning and not a report of a fact. You guys on that side are doing the same with me.
thanks for your posts, they are great by the way.
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Post by fattydash on Jul 7, 2011 7:10:25 GMT -4
Ok ka9q, consider this question. It is not a trick question. If Aldrin sighted a star from the lunar surface with the scanning telescope, and assuming there was no sunlight that would create glare were he to sight the star with his naked eyes, would he see the star through the scanning scope any better than with his naked eyes? Again this is not a trick question. I will tell you my answer after you tell me yours. I am not positive with regard to my answer, though I believe it is correct. So you can see how I think and why and I can see how you think and why and it may turn out we are both correct here, both wrong, or something in between.
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Post by trebor on Jul 7, 2011 7:11:52 GMT -4
I know that trebor. It was a leading question. Go on please. The other questions asked in that post, go on. Would it not be far simpler for you just to get to a point? If NASA tracked things so well... Did NASA have any way to track the LM during landing at all? I am unaware of any. The tracking as far as I am aware was entirely done by the internal computer, which due to a small oversight was giving an incorrect position. Add in the additional manoeuvres by Armstrong and there would be large error bars in the final landing position. With all that it would be unsurprising that it took quite some time for the observatories to locate the actual position of the mirror. As to the visibility of the lasers considering the width of the beam would have expanded to cover several square miles by the time it reached the moon I would be highly surprised if it was possible for even someone with perfectly night adapted vision to spot the diffused light by that point. That is even if the observatory managed to hit the location while they were on the surface.
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Post by fattydash on Jul 7, 2011 7:24:57 GMT -4
I agree. I imagine one could not see a ruby red laser from the moon, though I do not know that for a fact.
Since the argon laser was roughly as bright as Sirius and assuming more powerful laser could have been employed in 1969, I would imagine argon lasers could be seen. Since surveyor photographed the weak 1968 lasers, astronauts could have easily photographed all the more powerful argon lasers in 1969, should the scientists have viewed that as desirable.
Donald A. Beattie's book, "Taking Science to the Moon" is a worthwhile read. Beattie was/is a geologist and he dropped everything to be a member of the scientific team that designed experiments for the Apollo astronauts. He actually applied for a position as a "Scientist Astronaut" as did Jack Schmidt who became an astronaut. Beattie did not make the cut. Deke said no for some reason.
Beattie's book covers all sorts of great stuff. Indeed, they were worried about how one would find the Eagle. A device was created but not deployed on Apollo 11 that was very similar to the range finder in principle and when struck with laser light from earth, the device's lunar coordinates would be determined with great precision. Seems silly they did not have it on 07/20/1969. Perhaps it weighed too much. Beattie did not discuss why Armstrong did not pack it. He does give an account as to how they ultimately determined where in the world the Eagle had landed. I was surprised at how long it took.
I imagine the Eagle's coordinates that evening may have been determined with careful effective star sightings, though I am not convinced of this.
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Post by echnaton on Jul 7, 2011 7:58:38 GMT -4
Count Zero. Take a look at NASA's own web site "Lunar Science for Kids", not to mention many others. Many professional astronomers, including NASA astronomers point out that stars would actually be better seen from the lunar surface. So the best answer you have is to refer us to a web site for children? And not even a quote or link? That is what I call capitulation of a point. I don't think anyone would say stars could not be better viewed from the moon. In fact one experiment of the Apollo program was to make a photographic survey of the stars. The issue is how much better. You have failed to address that and until you make a quantitative claim here you are just handwaving. So as a direct question, how much better would viewing stars on the moon be? Please include a definition of what "better" means in the context of the Apollo mission and why your definition is relevant. Since you asked to "debate" the issue in another thread, here is your chance?
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Jul 7, 2011 9:09:25 GMT -4
The relevant quote is as follows. It comes from location 3594 on the Kindle ebook version. I have a paper copy, though do not have the book with me so cannot give you a page. Per astronaut Shepard and Slayton, Head of Astronaut Selection; " "Where were the stars?" the myth believers then asked. The cameras that NASA sent to the moon had to use short exposure times to take pictures of the bright lunar surface and the moonwalkers' white spacesuits. Stars' images, easily seen by the moonwalkers, were too faint and underexposed to be seen as they are in photographs taken from space shuttles and the International Space Station. " As I suspected, the above quote contains no context. It is impossible to know from the above under what conditions and circumstances that stars where "easily seen". Any further comment on the issue is unwise as it would amount to wild speculation.
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Post by fattydash on Jul 7, 2011 10:07:31 GMT -4
For Bob B. the context has to do with hoax debunking. This is from a section of the book dedicated to that.
Slayton/Shepard want to point out to those HBs that cannot understand why stars are not in the moonscape photos that the stars were visible, only not photographed due to limitations having to do with shutter speed, film speed and so forth. Slayton/Shepard are agruing, the stars were there, easily seen, just not photographed.
This is the context. This is their point. I make no claims as regards this point except that at face value, it contradicts the statement by Armstrong that he did not see stars, the statement that the only ojects visible in the lunar sky are the sun and the Earth.
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