Episode 11: Dust and Rock Claims of the Apollo Moon Hoax
Recap: Something as boring as rocks and dust has fueled many peoples' conspiratorial ideas relating to American's manned moon landings. Find out if they are well grounded.
Puzzler: One hoax claim that said there shouldn't be any dust on the moon at all. But there's another that states the dust is so deep that the astronauts should have sunk down to over their heads in it. In reality, we know that the depth of the lunar regolith does vary across the surface. Why isn't it uniform? After all, it's not like there's seasonal rain in some parts to wash it away.
Solution to Episode 9's Puzzler: (This was a bit of a trick question.) First, the basic idea is that the needle would follow Earth's magnetic field lines which are perpendicular to Earth's surface at either magnetic pole. So the needle would point straight up and down. But, the magnetic north pole of the compass is attracted to magnetic south poles of Earth. So, at Earth's magnetic north pole, which is in the southern hemisphere, the south end of the compass needle would point down and the north end up. At Earth's magnetic south pole, which is in the northern hemisphere, the north end of the magnet would point down while the south end would point up.
Q&A: Peter L. asks: "How can the source body of a meteorite be determined if we have never been there to check the place out. For example, meteorites credited to Vesta before we got there, and the post you did on the attempted tracing of the K-T asteroid to some break-up hundreds of millions of years ago. It sounds like magic."
Well Peter, the magic of which you speak is the magic of science. In this case, it's the same type as that needed to answer Jeff's question last time: Spectra. There's a saying that a picture is worth 1000 words. There's a less common saying that a spectrum is worth 1000 pictures.
Spectra allow us to measure the exact amount of light from an object at a specific wavelength and to draw out many of those wavelengths. In introductory astronomy labs, we show this by using basic filters like red, green, and blue, and we look at objects and see how much red, green, and blue light is reflected to build up a VERY coarse spectrum. You can go into finer detail, say instead of using broad red, green, and blue filters that may span several thousand Ångströms, you have filters that span a few hundred. Over the visible light range, this gives you a few dozen different measurements. Extend it beyond the visual and you get even more measurements.
You can use more advanced ways to separate out the light, just like a prism or a grating (think of the back of a CD for gratings). The bottom line is that we measure how much light is coming in smaller and smaller wavelength ranges.
When astronomers do this with asteroids, we see that asteroids fall into specific and distinct groups based entirely on their spectra, and these groups are loosely correlated with where they are in the asteroid belt or elsewhere in the solar system. Asteroids that were found early on are generally considered archetypes for different classes. For example, asteroid 2 Pallas is the archetype for the B-type asteroids within the C-group of asteroids. 3 Juno is the S-type. 4 Vesta is the V-type.
When we have meteorites on Earth, we can then look at their spectra to figure out which asteroid type they match. It's kinda like those little tree type booklets you get that has you make comparisons based on the leaves to figure out what tree you just ran into while you're waiting for the police to arrive. Coincidentally, Phil Plait, "The Bad Astronomer," has a blog post up the day I'm recording this that discusses just this kind of analysis, so I'm posting a link in the shownotes.
The second part of your question - tracing an impactor back that may have killed the dinosaurs - comes from two blog posts that I'll link to in the shownotes. To try to put it succinctly, the research in question was trying to figure out how long ago a particular asteroid family was created. A family is formed from the breakup of a single large asteroid, probably by collision with another one of comparable size. The fragments of that breakup will generally travel together along the same orbit as the original. But, over time, they will spread out. Based on this spreading, we can estimate how long ago it broke up.
In particular, there's a family of asteroids called the Baptistina which, according to a study in 2007, had a dynamical breakup time that would work well in models for sending a large fragment to Earth that would have formed the Chixulub impact crater and led to the demise of the dinosaurs and most other forms of life on Earth. A study a few months ago put this as less likely (again, please see the blog posts that I've linked to for more detailed information, including a message from the first author of the original paper).
So in the end, to get back to your question, this was a completely dynamical argument based on an asteroid breakup and timing for a fragment to get to Earth. In the end, it fits better into a, "We're proposing this 'cause it works," rather than, "We have good evidence that this is what happened." That's in contrast with the spectral technique for figuring out types of asteroids and pairing those with meteorites.
- Sources for Audio Clips and Quotes
- References Used and Additional Resources
- Resources for Terms and Concepts
- References and Resources for the Q&A
- Asteroid Types on Wikipedia
- Phil Plait's blog on Asteroid Spectra Usage
- My blog posts on the K/T extinction asteroid - "What's Going on with the Dinosaur-Killing Asteroid?" and "Follow-Up on the Dino-Killing Asteroid"
- Relevant Posts on my "Exposing PseudoAstronomy" Blog
Transcript of the Main Material:
Claim: There Shouldn't Be Regolith (No Process to Make It) The first of the dust and rock claims is short: There shouldn't be any lunar "dust" because the moon lacks wind and water to create it.
I think the theme for the dust claims is that your experience on Earth does not prepare you for what to expect on the moon, since that's the case here.
The material on the surface of the moon is mainly the result of billions of years of micrometeorite impacts onto larger rocks on the lunar surface. We call this material "regolith" as opposed to "soil" because the latter term is used in geology to indicate a more biological/organic origin. "Regolith" should technically be used to describe the surface material on all surfaces except Earth.
The process of creating regolith is usually referred to as "gardening" because the surface material is hit by extraplanetary/lunar material, it will be broken up and tend to move a little, and then the material underneath it can be hit. This in general creates a process of slow overturn where the upper several meters will be broken up regolith before you hit more competent rock. However, the depth of the regolith can change significantly over the surface of the moon.
It's also not just created by the micrometeorite impacts, but also larger impacts. A 1-km-diameter crater will produce a layer of ejecta that, after about 1 billion years, will become generally indistinguishable from the surrounding regolith except for maybe a slight topographic difference (ramp as you approach the crater rim). These larger impacts are rarer, but they do create significantly more future regolith material than the micrometeorite bombardment in one go.
Also, to a lesser extent, cosmic rays and solar wind will help generate regolith, as will tidal forces and some seismic activity, but they are very minor compared with actual meteoritic material.
Claim: Footprints and Rover Tracks in Water The next claim is that the bootprints and rover tracks appear to hold their shape very well, and they're darker than the regular material, so they must have been made in material that's wet. And, since there's no water on the moon, they couldn't've been made there. [Clip from Coast to Coast AM, March 20, 2009, Hour 3, starting 10:26]
Before I actually address the claim, this is a good example from which to take a moment to point out debate tactics. That Coast to Coast interview was recorded on March 20, 2009, where the hoax proponent was Bart Sibrel and the arguer was a caller into the program. In it, the caller was answering Bart about the question of why didn't camera lenses fog up on the moon when they went from hot to cold. I addressed that in Episode 5. As the caller correctly pointed out, it's because there's no moisture. Bart interrupted, changed claims, and went into the footprint claim which I'll address momentarily. He said there's no moisture in sand and so you don't get a footprint. The caller then tries to explain why you get footprints in dry material, but Bart constantly interrupts with inane "gotcha" points before accidentally admitting that everything on Earth has moisture in it, so his own example of sand isn't valid. He then changes the subject again before the caller could answer fully and goes on to creating vacuums in what seems like another "gotcha." What's very refreshing is that the caller actually pointed this tactic out -- it's known formally as "Moving the Goalpost" and more informally among skeptics as the "Gish Gallop." This was named after a famous creationist, Duane Gish, who during debates would jump from topic to topic to topic without ever giving his opponent an opportunity to answer or even acknowledging when that answer was given.
Anyway, about the claim, your experience on Earth does not prepare you well for what to expect on the moon. On Earth, if we try to think of something dry that we can walk in, most will probably think of sand in the desert or high up on the beach. And if you try to make a footprint in the dry sand, it doesn't hold.
If you pour your water into the sand, or if a big wave comes up, the sand gets a darker color. This is also usually the case for soil - it gets darker if it gets wet. You also know that as you walk on the beach where the waves wash up and the sand is wet, you can get the sand to hold a footprint. Or a castle. That's your common experience, and so that's apparently what the hoax proponents think should be the case on the moon.
But, that analogy doesn't hold. On Earth, sand is generally made of fairly smooth grains that roll around each other. They're smooth because they've been made by water and wind erosion that breaks tiny pieces of rock off and rolls and tumbles them around. They need a mechanical binding agent, like water, to hold a complex shape.
Lunar regolith is made mostly by impact events. There's no wind nor water on the moon, and so they don't experience nearly the level of further mechanical erosion that takes place on Earth. This means that lunar regolith is highly angular. When it's compressed into a complicated shape - like a bootprint - the individual grains fit together like puzzle pieces as opposed to like marbles, allowing them to retain the shape.
The reason it appears darker is two-fold. First, the shadows were very long during the Apollo missions because they were conducted close to lunar dawn, in part to keep the temperature down. Shadows make things appear darker. By definition.
Second, the upper layers of lunar regolith have been chemically weathered by cosmic rays which change their color. This is one of the reasons why old craters aren't surrounded by bright rays like some of the younger ones, like Tycho. If you go down below this layer that's been weathered, the material is a different tone; when the rover traveled and the astronauts bounded around kicking up material, they exposed this darker layer.
Claim: Dust Should Be Kicked Up Blinding them During Descent & Dust on the Lander Pads The next claim is that there should have been a bunch of lunar dust kicked up by the lunar module's descent engines that blinded the astronauts, making it impossible for them to land.
This claim is followed up by the claim that is one of the most prevalent of the dust-based hoax ideas: [Clip from Bart Sibrel's "A Funny Thing Happened on the Way to the Moon"]
This is yet another case where your common sense from your experience on Earth does not serve you for what to expect on the moon. On Earth, if you fire a rocket engine towards the ground, you'll get a huge cloud of debris. If you want to see this effect, take a small tray, put flour in it, and put it in the bathtub. Take a can of compressed air, put the little red straw in it, aim the straw down towards the flour, and spray the air. You'll see a huge cloud of flour be kicked up ... this is why you're doing it in the bathtub. Or do it outside.
If you do this experiment, you'll see the cloud of flour linger in the air for quite some time. So your every-day experience would tell you that lunar dust should act the same way.
The difference is keyed into what I just said: "The cloud of flour will linger in the air." The moon has no atmosphere to speak of. The only reason that dust is kicked up and suspended briefly around the descent module is that the engine exhaust is CREATING a temporary atmosphere. As soon as the engines were cut off, the temporary atmosphere went away, and the dust settled at the speed of free-fall in lunar gravity.
The lander was still descending, but it also was not just descending purely straight down. It had a horizontal component, as well. So these combined effects - the dust settling very quickly and it settling where the lander WOULD HAVE BEEN rather than where the module ended up due to the horizontal motion - are why we actually would NOT expect there to be lunar material on top of the lander's footpads.
Claim: Geologists Don't Know What to Look For So Can Be Fooled The first set of rock claims goes from basic conspiracy to what a normal person would likely consider to be paranoid delusions.
First, there's the idea that geologists have never seen lunar rocks before, so they wouldn't know a genuine one from an ordinary Earth rock or one that had been somehow fabricated.
Stepping up the conspiracy level is the claim that geologists are all trained in government-funded and -controlled universities. If the government wanted to keep the true nature of the lunar samples secret, it could easily control what geologists know and learn.
The third claim is the paranoid one: The US Government threatens any geologists with terrible consequences if he should reveal that the samples he obtains from NASA are not actual factual lunar surface samples.
I can't help you if you believe the last point. IF you do, you might as well turn off this podcast because I'm sure you believe I'm on the take. After all, I did just buy a $400 chocolate tempering machine. People are going to like me this winter solstice.
If you've heard either of the first two, the claim basically boils down to, "Geologists don't know what they're doing." And to put it bluntly, this isn't only an insult to geologists, but it's an insult really to all of science and the basic way science is done.
Physical sciences like geology are done based on observation and experimentation. For example, a geologist will go to the Rocky Mountains, chip off a piece of rock, and study it. They'll go to a volcano, chip off a piece of rock, and study it. They'll go to a riverbed, chip off a piece of rock, and study it. They'll look at the differences. They'll try to figure out why there are differences and how those differences were made.
From geologists having done this for hundreds of years, they've built up a pretty good idea of what's going on with Earth rocks. They can then apply that knowledge to hypothesize what they would expect from a surface they've never sampled before, such as the moon. They can also figure out what kind of environment rocks formed in, like if there was an atmosphere.
The hoax claim that geologists could simply be presented with a rock, told it's from the moon, and then go with it when it was really just an Earth rock simply illustrates a profound lack of understanding of how science is done.
There's also radiometric dating, but I'll get to that after the next claim, which is ...
Claim/Independent: Rocks from Antarctica or could've Sent Sample Return ... we could have sent sample return missions to get the moon rocks. After all, the Soviets did! Or, if you don't like that, behind Door #2 there's the idea that the rocks were just collected from Antarctica.
There are actually a few main problems with these. The reason I put these two claims together is that the first problem deals with both, and it's the economy of scale: Apollo returned HALF A TON of moon rocks, 385 kilograms. At the moment, we have less than about 60 kilograms of meteorites that came from the moon (16% Apollo sample), while the soviet sample return gave us a total of 270 grams. That's grams, not kilograms, or about 0.07% as much material as the Apollo astronauts returned.
So there's that. Lots of rocks versus few rocks.
Building on that, the second reason we could not have used sample return to get these samples instead of from Apollo astronauts is that the technology to return half a ton of rocks from another planet does not exist. It did not exist then, it does not exist now. The Japanese probe Hayabusa returned about 1500 tiny grains of material from an asteroid last year. The soviets returned a bit over half a pound from the moon over several missions in the 1970s. The proposed Mars sample return mission that wouldn't happen for at least decade is talking about a few small rocks - nothing close to a ton.
The second problem with the collection from Antarctica has to do with what are called "zap pits." Zap pits, which are impossible to say quickly, are tiny craters in the surfaces of rocks. These form from micrometeorite impacts that aren't strong enough to destroy the rock, but they chip off tiny pieces and create the lunar regolith. What they leave behind in the rock are these tiny craters.
Zap pits can ONLY form if there are micrometeorite impacts. Those can ONLY happen if there is no atmosphere. Even Mars' tiny atmosphere is enough to prevent the impacts that would form zap pits from reaching the surface. But they do form on the moon.
The Apollo and Luna returned samples all have zap pits. Meteorites from Antarctica don't. They don't because as a rock travels through Earth's atmosphere, the surface heats up to very high temperatures, and a thin outer part of the rock melts. This forms what's called a fusion crust - basically the melted rock - and it eliminates all zap pits.
So again, the fact that the Apollo sample returns have zap pits, and the Antarctic returns don't, indicates that indeed, these were collected from the moon, by astronauts, and not by explorers in Antarctica.
Independent: Ages of Rocks In a purely independent way - that deals with rocks or dust - to show that we went to the moon with Apollo is to look at the ages of the rocks that were brought back. The oldest rocks dated on Earth are presently around 3.5-3.8 billion years old. In contrast, the youngest age of the moon rocks returned is about 3.2 billion years old, but most are around 3.8-4.5.
I'll repeat that: We have a plethora of moon rocks - returned by Apollo for reasons I discussed in the last claim - that date to several hundred million years before the oldest Earth rock. You can't fake or manufacture a rock that gives this kind of radiometric age.
Independent: Apollo 16 "Grand Prix" Maneuver A second independent way to tell that we went to the moon is to look at the Apollo 16 "Grand Prix" maneuver on the rover, so-called because they basically floored it to see how fast the rover could go and how it performed. In the video, which I'll post to the shownotes for this episode, you can see the rover moving and kicking up a bunch of dust.
IF it were recorded in an environment that had an atmosphere, the dust would have to billow out because it would be supported by air and the tiniest of air currents would scatter the dust at least in some way.
But one could argue it was recorded in a vacuum chamber.
IF it were recorded ON EARTH, though, the dust still wouldn't behave as it does in the video. In the video, the dust follows a perfect, introductory physics parabolic arc. It goes up, slows down, comes to an apex, and falls back down to the surface. If you ever took introductory physics in high school or college, you may remember the basic equation for ballistic motion. In that equation is the term for gravity. So you can actually follow the dust and figure out the gravity field that it was filmed in which comes out to be the moon, not Earth.
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