# How do we know the Apollo Moon landings are real?

In order to spare the energy of this community by addressing this issue once and for all, can we summarize the numerous reasons why we know the six Apollo missions did indeed land on the Moon and return 18 astronauts to Earth?

• Welcome to our wiki Q&A on the Apollo Moon landings! Please feel free to contribute to making this post stronger (both the question and answer). We encourage you to discuss large changes on meta. If there are disputes over the content, the posts may be locked temporarily to resolve. Jun 28 '18 at 20:13
• If you read (and can believe) the Wikipedia article on the movie "Capricorn One", the whole conspiracy theory idea could have spawned from the musings of Peter Hyams - not based on any "suspicious evidence" as the conspiracy theorists like to trot out, but rather just a "what-if" that made for an entertaining movie. Jul 1 '18 at 18:02
• I really wish this wasn't something that still cropped up in casual conversation about space with people I care about... Jul 19 '18 at 19:44
• @MagicOctopusUrn There are just too many people for it not to be an issue. I think the sentiment in xkcd.com/1053 should apply here. Although I understand many people consider "conspiracy theories" in a special category of unmentionable subjects for some reason, doing very little to dispel them. Sep 27 '18 at 13:28

As belief in conspiracy theories is associated with the rejection of science, it is likely that this answer will be rejected by many at the outset. If you doubt the reliability of science, perhaps you should check out this NPR article. Please note that it is an opinion piece. The author Alva Noë is a professor of philosophy at UC Berkeley, not a journalist. Use your own reasoning to honestly consider his words.

If it is not the scientific method itself that you distrust, but the "scientific establishment", then you should consider the way science works. All papers are subject to review, all results are expected to be repeatable and independently verified. Individuals can and have created independent groups to ensure the integrity of their work. If there is not a significant group of scientists with expertise in a particular domain that reject a conclusion from that domain, then it would be prudent to provisionally accept that conclusion.

How, indeed, can we believe that anything we did not personally witness, did in fact happen?

That's a trick question...critical thinkers don't have to "believe" anything. As paleoanthropologist Dr. Briana Pobiner (quoted here by Adam Blankenbicker) replied when asked "You believe in evolution, right?" -

"I don't believe in evolution - I accept the evidence for evolution."

The believing isn’t what makes evolution true or not, it’s that there is evidence that supports it.

One of the obstacles to belief in any space enterprise is belief in a flat earth. Those who believe in a flat earth are aware of the idea of orbits and of images returned from space of the globe. Because of this, they assert that NASA must have faked the moon landing, as they reason the whole space enterprise must be a conspiracy to begin with.

However, since we accept science, it is easy to dismiss the possibility of a flat earth. First of all, for the dedicated and resourceful, it is possible to fly around the Earth without stopping. This may be prohibitive for the average reader, but as we discussed above, we don't have to personally witness something to accept the evidence for it. If you're interested in the evidence for a round earth, Moriel Schottlender provides a good summary on her site SmarterThanThat.

There are many reasons we know the Apollo missions landed on the Moon and returned. Here is a list summarizing the main ones:

## 1. The science of space rocketry is sound.

For the layman, a common area of confusion is how rockets work in space with nothing to push against. However, the scientific principle for why this works has been understood for a long time (Newton's third law). For more information see:

Some have heard that there was scientific skepticism prior to the launch of Sputnik, but this was rooted not in doubt of Newton's laws but in concerns of the financial viability of the enterprise:

How widespread was the notion that space travel was impossible prior to the successful launch of Sputnik 1? - History Stack Exchange

Furthermore...

## 2. The science we use to model and build rockets is the same as we use on Earth

The methods we use to model space flight - in particular the chemistry and thermodynamics of rocket engines - are used in every field of engineering.

The way we model the boiling of a kettle allows us to predict and demonstrate that an engine produces thrust in a vacuum. These models are not in question; one might as well claim that the engine of a car cannot function according to physics as claim the same for a rocket engine.

## 3. It is clear that humans have been to space.

The International Space Station can be viewed by amateurs from the ground. With dedication, astronauts can even be spotted on spacewalks:

How would one go about proving humans have really been to outer space? - Space Exploration Stack Exchange

That said, some are willing to believe we can go to space today, but doubt the possibility of what was accomplished in the Apollo era. That leads us to...

## 4. There is a wealth of third-party evidence for the Apollo Moon landings.

The Soviet Union, Japan, China, and India have all, independently of NASA, verified the Moon landings. Wikipedia has a convenient collection of this third-party evidence. The Wikipedia article is well-sourced, and thus acts as a repository of information that has been gathered from places such as JAXA's website, an Indian academic journal of research, and Xinhua News Agency. It is beyond belief that there could be a conspiracy this vast to maintain a fake moon landing story. There could not even be a reasonable collective motivation. China aspires to land a manned expedition on the Moon, and they would love to one day have the opportunity to claim that they were truly the first; yet even China affirms the account of the Apollo expeditions.

One key piece of third-party evidence comes from the retroreflectors left on the Moon by three of the Apollo missions (11, 14, and 15) and by two uncrewed Soviet lunar landers. These retroreflectors have been pinged from dozens of sites all over the world; they are exactly where the US and the Soviet Union said their vehicles landed. The existence of the retroreflectors does not prove that the three US missions were crewed, but it does prove that some kind of landings occurred at those three sites.

The above points show that the Apollo program could have been taken place, and that there's lots of evidence that shows that it did take place. Could it have been fake? This leads us to ...

## 5. The technology needed to fake the Moon landings did not exist at that time.

The Apollo astronauts took an abundance of photographs during their short stays on the Moon. The photographic evidence is very compelling, which compels the conspiracy theorists to try to debunk those photographs. These efforts inevitably fail; the lighting in every single photograph taken from the surface of the Moon is consistent with a bright light source one astronomical unit away and is inconsistent with studio lighting.

Those photographs could of course have been created as computer-generated imagery. CGI has recently been used to recreate some of the iconic photographs taken from the Moon. One of the two photographs below was taken by Neil Armstrong. The other is pure fantasy, generated by a computer.

The technology needed to produce those photographs as computer-generated images is very new (late 2014, to be precise), and even then, it wasn't easy. Such technology did not exist twenty years ago, let alone fifty years ago.

• and they would love to one day have the opportunity to claim that they were truly the first; yet even China. I'm unsure why this has been limited to China, I feel like I can state with almost clear certainty that everyone would like to claim that they were truly the first, not only China. (Although I may be misunderstanding your intentions here) Jun 29 '18 at 6:38
• If the USSR had had just a tiny amount of doubt whether the landings were faked, they would have used that for propaganda. Loudly! They observed the landings closely and even had a spacecraft in orbit during Apollo 11's landing. Jun 29 '18 at 7:06
• @DarkDust you've piqued my interest, so I've asked In what ways did the Soviet Union “observe the Apollo Moon landings closely”?
– uhoh
Jul 1 '18 at 16:47
• Regarding third party evidence, here's an image: ilrs.cddis.eosdis.nasa.gov/images/… . These are the sites that have pinged the retroreflectors left on the Moon by two of the Apollo missions and by one unmanned Soviet mission. Aug 17 '18 at 15:34

Conspiracy theories generally depend upon an absence of critical thinking. Any reasonable debunking generally requires critical thinking to cut through the misdirections, false assumptions and flawed logic upon which these theories are inevitably based.

Nevertheless...

To execute a hoax, there is need of means, a motive, an intended target, and some expectation of success.

Who would be the intended target of such a hoax? The American public? The Soviet government? The general public of the world?

If the Americans had a motive and a target for a hoax, it would have been to make the Soviet Union think they had achieved a manned Moon landing without actually doing so. The snag here is that the effort to actually execute such a hoax (without it being discovered) would probably be greater than the effort to actually do it for real. Add to that the embarrassment should such a hoax ever be unmasked. The Soviets could easily tell if a radio signal was coming from a transmitter on or orbiting the Moon vs local to Earth. They knew what it would take to put a man on the Moon - they had their own lunar landing program (conducted in secrecy to avoid the embarrassment of a public failure). The Americans could not realistically have executed a hoax without the Soviets seeing through it and calling them out.

The Moon landings occurred in the context of the Cold War Space Race. The Soviet Union, like the US, was developing nuclear bombs and the long-range ballistic missiles needed to deliver them onto targets pretty much anywhere in the world. As this was going on, the Soviets launched Sputnik, the world's first artificial satellite (which could be easily tracked by radar and even seen under the right light conditions, despite its small size). No question this happened. As the Soviets continued onward to put a dog and then a man in space, the US found itself trailing behind. As they were fighting their way back toward parity, Kennedy made his famous Moon speech. The intent was to get out in front of the Soviets and do so with a clear demonstration.

The purpose of the lunar landings was to put a man on the Moon as a show of technological superiority. The point of it was not to merely make the Soviets think they had landed on the Moon, but to actually go and do it in full view of the world. The American effort was transparent in terms of what was being done, when, and why during each space mission, giving the Soviet Union (and anyone else who cared to audit the exercise) ample opportunity to verify exactly what was really going on.

The Soviets would have liked nothing better than to disclose an American hoax if it indeed was one. The fact that the Soviet leadership congratulated the Americans on their success, rather than even suggesting anything was not as claimed, speaks to the fact that everything was exactly as it appeared to be.

FWIW: I was 10 when Apollo 11 flew. I watched it all on TV, broadcast live as it happened - the launch, the lunar landing, Armstrong's first step, the splashdown. My memories aren't fake, Walter Cronkite's reporting wasn't fake. Anyone too young to have at least had that experience might be open to the notion that it never happened, even retroactively faked, but even as a 10-year old, I understood a lot about what was going on and just how real it was. The first space launch I can remember watching was Apollo 7, and I've enthusiastically followed the American (and other) space programs since then. I've read countless articles and watched endless hours of documentaries on space technology and space exploration, studied engineering, and built my career in computer technology. I am wholly satisfied the "official" public record stands unimpeached and unimpeachable.

In addition to kim holder's big post showing that we have been to space, there's the other side of it: We couldn't have faked it.

1. The stage needed is far beyond anything we have built to date. To get the dust to behave correctly it needs to be in vacuum. To get the light even close to right it has to be huge because you need a very distant point source of light.

2. What is that source of light? What do we have that is bright enough and focused enough for the job?

3. Running the camera overspeed makes the motion of the body look like it's in low gravity. However, doing this will also slow down limb motions and thus it doesn't look right.

4. We had long, continuous broadcasts during the mission. To fake that we need a camera that can record that long--and nothing close existed back then. Did they somehow manage to develop such camera technology in secret and then make it disappear? Technology doesn't just vanish like that.

• There's a nice video explaining why the slow-motion video techniques that would have been needed to produce fake moon landing videos simply were not available at the time (the interesting part starts around 4:33). Jul 2 '18 at 10:58
• @DarkDust Consider editing this into Loren's answer. It is a community wiki, so it is for everyone to modify! Jul 19 '18 at 13:25

# How to fake a moon landing project in the 1960s

To attack this issue from a different angle, consider the minimum required manpower necessary for such an operation.

## Minimal Personnel in-the-know

During the Apollo Project, there were over 400,000 people involved in a conspiracy that was conducted over a period of more than a decade. If all of those people were "in-the-know" during this period, there is an extremely high risk of compromise.

## Only the astronauts and a small film crew were required to fake the moon landings.

Let's go down the check list, in order to make that happen:

• Astronauts, acting out the entire multi-day flight while actually in earth-orbit
• Film crew recording the fake landings
• Construction crew to build a set OR security team to secure a remote filming location (desert)
• Manufacturing team to produce material recovered from the moon landings
• Photo editing team to produce photos of the moon taken by the CMP during Lunar Orbit
• All photo and video evidence needs to be shot and verified before the flight- the astronauts will be busy constructing false radio data convincing enough that mission controllers don't notice they aren't actually landing.
• Skilled telemetry experts to send fake telemetry data to mission controllers in real-time, for the entire duration of the flight. (Note that this data must be accurate enough to fool mission controllers, who are world-leading-experts in reading and interpreting the data. It must look like a circumlunar flight, landing, rendezvous, etc, rather than an earth orbit flight)
• Entirely overhauled spacecraft controls and switchpanels - If the astronauts are actually in earth orbit rather than landing on the moon during the flights, some switches need to be safely disabled. All of the switch positions need to be accurate through the entire duration of the flight, but thrusters and rockets related to Trans Lunar Injection, Lunar Orbit Insertion, Landing, Ascent, Rendezvous, Trans Earth Injection, must not actually fire, but anything needed for re-entry must work properly
• Fake seismic data for the Apollo 13 third stage impact event on the lunar surface
• Accurate, reliable, convincing, but ultimately falsified, ALSEP data - a continuous data stream for 8 years from multiple supposed ALSEP packages on the lunar surface OR the ALSEP packages must actually be on the moon, requiring an incredible number of people in order to secretly build, launch, and land these on the moon
• At the fake Trans Lunar Injection burn, the spacecraft would then need to be hidden from radar detection by other countries monitoring the event- and would need to remain hidden for the remaining week of the earth orbital flight. Additionally, radio transmissions (both voice and telemetry) would need to appear to be coming from deep space and Lunar orbit as opposed to Earth orbit. The Doppler Effect would quickly reveal the true source of these transmissions. (Thanks to Anthony X for pointing this out)
• A lifelike spacecraft would need to be en-route to the moon during the Apollo 11 mission, as the Soviets launched their own probe that was en-route to the moon at the same time as Apollo 11. A spacecraft of similar proportions would need to be on the proper trajectory to prevent them from uncovering the conspiracy. Countless staff would be required to operate this ruse. (Thanks to Anthony X for pointing this out)
• In addition to the things needed to create a false representation of a true moon landing, extra drama was injected during some of the flights, with astronauts and controllers responding accordingly. (Apollo 11's 1201 & 1202 alarms, all of Apollo 13's accident, etc) This adds a whole host of complexity and additional actors for those events to be pulled off skillfully enough to uphold the deception.

If you think of something more that could be added to this list, leave a comment. Faking the landings would be an unimaginable task, with the amount of information we have from the flights, and the number of people that would have to be involved to fake this massive, publicly visible operation.

• You've neglected to consider the logistics of faking the mission before an international audience of space experts, especially in what was then the USSR, who had already flown multiple space missions and had launched a lunar probe at about the same time as Apollo 11 (both were enroute to the Moon at about the same time). Spacecraft radar returns and telemetry would have to be faked, a vehicle launched to Earth orbit but never executing TLI would have to be masked upon the bogus TLI event, and it goes on... Jan 20 '19 at 19:44
• But faking would not end after the Apollo mission. Faking the presence of the lunar retroreflectors during all the years up to now would be extreamly difficult. Not only for a single national telescope but for all international old and new telescopes doing lunar laser range measurements.
– Uwe
Jan 20 '19 at 22:25
• @Anthony X, I directly mentioned fake telemetry and bogus data for TLI, LOI, TEI, and more. The probe info is good, but I don't know what you're trying to say with the telemetry and TLI comment... Jan 20 '19 at 23:01
• @MattZabojnik Your wording suggests that the NASA mission controllers are the targets of the deception, where the true targets of the deception would have to be anyone and everyone in the world capable of eavesdropping on would be a real mission e.g. the Soviets. Jan 21 '19 at 0:01
• I've always thought this was the most compelling answer to moon landing deniers. The execution of the hoax would have been on par, or harder, than the actual moon landing. Jul 22 '19 at 18:58

The conspiracy theorists who claim the Moon landings were faked put forward a few selected artifacts of questionable provenance or authenticity and call them evidence. They interpret this "evidence" according to unsupported and arbitrary assumptions and then deem the resulting conclusions irrefutable.

To refute the historical record, every piece of evidence in existence (and there is a lot of it) must be challenged objectively and rigorously. There must be no assumptions; every conclusion must be drawn from sound logical reasoning and solid fact.

Along with all that is described in other answers, consider that our space program rivals at the time, who would have been keen to expose a hoax, had their own lunar explorations with which to compare the NASA claims.

Begin with the Soviet Union's Luna 3, the first spacecraft from any nation to successfully reach and orbit the Moon. Luna 3 did not land a man (or woman) on the Moon, it merely provided the first views we ever saw of the far side, views with which the Apollo orbiters' "purported" Far-side images could be compared.

Later Luna missions landed unmanned craft on the Moon and even returned to Earth with samples. These automated return samples were small compared with the rocks "apparently" brought back by the Americans, but a comparison of mineral compositions was still possible.

We have more than just congratulations from the Soviets as evidence that they, who would have been motivated to do so, never claimed a hoax. We have positive comparisons between their data and ours to corroborate both the Soviet and American lunar exploration claims.

• This is mostly the same as space.stackexchange.com/a/28199/20636 - but comparison of lunar samples is a useful addition. As that answer is a community wiki it would have been better to have edited that answer to add this detail.
– user20636
Jan 22 '19 at 6:38

How do we know, the conspiracy theory is real?

Conspiracy theories present some facts as "evidence", neglect all facts that weaken or disprove their arguments. Also, the conspirators are some untangible dark group.

The closest real-life equivalent of a conspiracy, in the sense of conspiracy theories, are cartels, i.e. groups of companies who enrich themselves by price fixing and other nefarious practices.

How do we know that cartels exist? The are more or less frequently uncovered. Either by some actor(s) seeking crown-witness benefits, or by law enforcement. In any case, cartels come to light, given enough time. Thus, we know of their existence and we are not consigned to believe in them. They are real.

All the conspiracy theories claim some conspiracy against humanity, or a smaller subset thereof, yet, no conspiracy theory ever proofed to be

All in all, I find the conspiracy theories lacking. They claim the moon landing was faked, yet there is no evidence of large-scale collusion. All the supporting evidence are some weird artefacts in the photo-graphs, the behaviour of the flag, ... (you know it all).

If all lightbulbs in the supermarket cost nearly the same, what's the reason for this?

• A conspiracy, i.e. cartel, of the major or all lightbulb producers
• Mere coincidence, since all manufacturers operate with a very slim profit-margin, and the labour and material costs can't be driven further down.

Feel free to apply Ockham's razor.