Debunking the Moon Truthers, Part 2

by Brian Dunning
September 13, 2016

The Horrible "Evidence" that We Never Went to the Moon

This is the second installment in an unprecedented three-part Skeptoid episode about the Moon Landing Conspiracy. Last week we talked about the history and character of the conspiracy theory, and next week we're going to look at the physical evidence that proves man went to the moon. But this week we're going to talk about that part of the conspiracy you've probably heard the most about, and that's the various claims of glitches and errors that supposedly suggest the Apollo program was a hoax that never happened.

Let's launch right into these, starting with the first major problem that the Moon Truthers say the astronauts could have never overcome:

It's impossible for humans to leave low Earth orbit, due to the lethal radiation in the Earth's Van Allen Radiation Belts.

The Van Allen Radiation Belts are rings around the Earth's magnetic pole, tall and thin rather than flat like Saturn's ring. They consist of charged particles magnetically trapped in place. While it's true that the Van Allen Belts are a high-radiation zone and a dangerous place to loiter, astronauts can go through them in about an hour. Even without any special radiation shielding, this trip exposes astronauts to about 1 rem, about the same as 100 chest X-rays. This is about 20 times what a US nuclear plant worker is allowed to receive in a year, so it's above normal safety levels. But not catastrophically so. You would need to get 100 times that much to develop the first signs of radiation sickness. The astronauts were all well aware of this, and considered the trip well worth the risk.

We should not have been able to hear the astronauts talking during the Lunar Module descent, because of how loud the rocket motor would have been.

Seemingly true; rocket motors are insanely loud, and if you're sitting just a meter or two away from one it would be pretty hard to hear yourself think. Yet the Apollo astronauts calmly narrated their descent over the radio to mission control, with no interfering roar.

Obviously there's no air and thus no sound outside the craft, and on Earth, almost all of a rocket's noise comes from shearing action between the exhaust jet and the surrounding atmosphere. With that taken out of the equation, rockets are much more peaceful. Significant vibration did transfer through the structure to the astronauts during descent, but comparatively little noise. In any case, their microphones were inside their insulating helmets, mounted close to their mouths, with audio patterns designed to pick up only extremely close sounds. There is no reason to expect their voices would have been drowned out by rocket noise.

All photos of the Lunar Module on the surface must be fake, because the blast crater created by its landing rocket is missing.

No blast crater would be expected, although this seems admittedly counterintuitive. When the Lunar Module came in to land, it came in with horizontal velocity as the pilot searched for a place to land. Once he found one, he descended, throttled back, and a probe extending over a meter below the landing pads touched the ground and shut off the rocket motor. It was only a very brief moment that the rocket nozzle was actually directed at the landing site, and only at reduced power.

Even so, the moon's surface is not very prone to disruption. Although we see astronaut footprints in a dusty surface, that surface dust is quite thin. Below that, the regolith is much firmer. Probably a small amount of surface dust was displaced below the lander, but not very much.

The Lunar Module's landing rocket also would have blasted all the dust away from the area, so the astronauts wouldn't have left any footprints.

There's no air on the moon and no shockwaves. Nearly all of the wind and turbulent clouds you see at a rocket launch are the result of air being pushed by the rocket exhaust, and pushing other air, and so on. To fly, the rocket only needs the reaction. It does not require things on the ground getting blown around, and if there's no air or wind to do it, it won't happen.

Gas from the rocket nozzles expands very quickly in the vacuum of space, and the descent motor had a wide dispersal pattern. You probably could have sat in a beach chair a few meters from the Lunar Module as it landed, and not felt much.

The astronauts' footprints are so deep that the heavy Lunar Module must have sunk in much deeper.

The footprints weren't all that deep; a centimeter or two at most. And although the various Lunar Modules did weigh some 17 to 19 metric tons when fully loaded on Earth, on the moon that was down to about 1200 kg after burning off fuel. That weight was distributed on four 1-meter round footpads. The pressure exerted on the surface by the footpads was only about half again as much as by the astronaut's boot soles. So the Lunar Modules would be expected to push a little bit deeper into the surface than an astronaut, but probably not a noticeable amount.

The American flag they planted is flapping in a supposedly-nonexistent breeze.

By now we've all heard that the flag was held by a rigid metal rod to compensate for the lack of wind on the moon, but it's worth mentioning that in some of the video footage, the illusion of air movement can be quite remarkable, and it's worth watching. But the cause is embarrassingly obvious: in all such shots, an astronaut is either actively twisting the flagpole to get it set up, or he bumps it. This is one claim that really needs to just die already.

Sometimes you'll see a photo of one astronaut with the other reflected in his helmet visor, and neither one of them has a camera up to his face taking a picture.

Proof that a conspiring studio photographer was present on the set taking these pictures? No, proof that the cameras were mounted to the astronauts' chests.

Stars would be visible in all the photos if they'd really been taken from the Moon.

No they wouldn't, because the cameras' exposure settings were adjusted for bright daylight, giving a very small aperture. To capture stars, you need a very large aperture. Test it for yourself: Set your aperture, ISO, and exposure so that you're taking great pictures in the daylight. Then with the same settings, try to photograph anything at all at night. Blackness.

It's impossible to take any photos on the moon with a film camera, since film would have melted in the 120°C/250°F surface temperature.

Regular cameras and regular film, yes. But the Apollo astronauts used cameras and film specially made by Eastman Kodak. The cameras were heavily insulated against temperature, and the film had a much higher temperature range. Imagine, NASA actually thought of this before the conspiracy theorists did.

The light source in the photos is not the distant sun, because there are non-parallel shadows.

The photos did show non-parallel shadows, because of a little thing we call perspective. Look at a fence with the sun behind you, and the shadows of the fence posts will appear to converge; look at the fence with the sun behind it and the shadows will appear to diverge. No mystery here.

Some shadows are long while others are short, again proving the distant sun is not the light source.

This claim is mainly based on a couple of photos of astronauts where their shadows extend to the top of the same mound, even though one is closer to it than the other. The reason is simply that the ground undulates. The length of a shadow depends on the angle of the sun relative to the angle of the ground, and on an undulating surface, we absolutely expect objects of the same height to have shadows of different lengths.

Studio lights are visible in the background of some photos.

There are indeed bright spots in the sky that look exactly like lights in some of the photos. Photographers know what they are: they're called lens flares, which can appear when bright light reflects between the lens surfaces inside the camera. The type of lens flares in the Apollo photographs form in a line leading toward a bright light source just outside the frame, in this case, the sun.

The studio lights cause hot spots on the surface of the moon.

In some photos where the photographer's shadow is visible in the frame, there are unusually bright spots on the moon surface around the shadow, suggesting that a studio light must have been focused on that spot.

Proof of a conspiracy? Nope. These hot spots are called Heiligenscheins, a German word meaning halo. You can see it any time you look at the shadow of your own head, sometimes more dramatically than others, and often better from a greater distance. You've seen it from a plane when you look down and see the plane's shadow with a strangely bright area around it. Heiligenscheins are caused by two different effects. Looking at the shadow of your own head, the light source is directly behind you. Everything directly outside that shadow — blades of grass, pebbles, whatever — has the light hitting it from an angle very close to your viewing angle, so shadows are foreshortened almost to zero. Objects farther from your shadow are less foreshortened, so there is more and more shadowed area visible in your field of view. Thus the overall light level is always going to be highest closer to your shadow, and progressively darker the farther away you look.

The second effect causing Heiligenscheins happens when the surface is reflective; moon regolith would be one example, dewy grass another. It's called backscatter. A greater proportion of light (and other radiation) is always bounced back in the same direction from which it came, which is why radar works. When you look at the shadow of your head, backscatter sends more light toward you from objects on the ground closest to the shadow. The farther away those objects are, the less of their backscatter is going toward your eyes. Combine these two effects, and the Heiligenscheins we see in the lunar photographs are exactly what we'd expect to see if they were genuine.

One rock was accidentally left showing the letter C written on it, proving it was a prop.

No, it wasn't. Photo analysts have concluded the most likely explanation for this apparent letter C on a rock is a hair on the original photo print. To say nothing of the fact that no Hollywood prop master ever heard of labeling inventory by boldly writing letters of the alphabet on camera-facing surfaces. Anyway, for presumed hoaxers to use a commercial Hollywood prop shop for a moon landing set would have introduced another unnecessary risk: more outside people who would have known about it, and a paper trail for the prop rental. Smart conspirators would have built the set themselves, with rocks they trucked in themselves.

Those are the basic answers, but there are many many more such claims and we would have had to make this a ten-part episode to cover them all. But we really don't need any more, because next week we'll continue by looking at the scientific proof that we actually did put humans on the moon.

By Brian Dunning
Follow @BrianDunning