AboutDr Thomas Bell Expertise I can answer questions regarding surface earth processes and the chemical transformations that sediments and rocks undergo with burial. I can also answer questions regarding deep time, the evolution of the elements, and the last 4.5 billion years of earth history. I specialize in metallic ore forming processes, the major geologic time periods when they were produced and what they tell us about the evolution of our planet. Learn more about my professional interests at Stratamodel.com.
Experience I am a professional consulting geologist with a background in the petroleum, mining, environmental, and geotechnical industries with over 25 years of experience.
Education/Credentials Ph.D., Geology, University of California at Berkeley, 1984
M.A., Geology, University of California at Berkeley, 1980
B.S., Geology, San Jose State University, 1978
Today I had a debate with a co-worker regarding whether or not the United States successfully landed on the moon. While my adversary in this debate does not specifically claim that the moon landing was faked, he does state that he has not seen any evidence of a landing that he finds conclusive, and that therefore his mind is open to the idea that the United States failed to land on the moon and decided to fake the landing. I know that one of the primary goals of the Apollo missions was to return lunar rock samples for study. I also know that lunar rocks blasted from the surface of the moon by impacts eons ago have found their way to Earth, survived the encounter with our atmosphere, and been found and studied by scientists. My co-worker admits these two facts, but argues that the moon rocks that were supposedly returned by the Apollo missions may have actually just been collected from Antarctica as part of a moon landing hoax. I find that argument to be specious at best, but I currently have no way to shoot it down.
Are there any processes that occur ONLY on the moon, or ONLY on Earth, that would in essence provide a kind of signature that scientist could use to differentiate--without question--between a moon rock that found its way to Earth as a result of natural processes and a moon rock that was returned by an Apollo mission? In other words, is there a way to identify moon rocks that could only have reached Earth in an Apollo module?
Thank you for any time that expend on this question, and for any insight that you can provide.
--Tom
Answer Tom,
I doubt that you can convince your adversary of the authenticity of the Apollo program and I suggest you challenge him to prove his hypothesis that Apollo was a fake. After all, the fake moon landing conspiracy theory is an extreme minority opinion that few people take seriously.
When I was in graduate school at Berkeley, several professors in the department had more or less completed a decade of study of samples returned from the moon by the Apollo program. These samples collected at great expense and personal risk where distributed among the most distinguished experts in the geologic community and I seriously doubt that any rock collection before or since has been subjected to the degree of scrutiny that these lunar rocks were.
Aside from the obvious documentary evidence (photos and film) of Apollo astronauts exploring the moon and the grudging ackowledgement by our geopolitical rivals of that era, a vast literature exists enumerating the results of every measurement possible of these historic samples. So, lets start with a list of the features of these rocks that link them to Earth's moon.
Lunar rocks that have found their way to Earth are pretty obvious. They get pretty hot before landing on our surface. This leaves telltale signs like melted surfaces and oxidation. In short, they are easily distinguished from rocks collected on the Moon.
Lunar rocks are old, real old. In fact the oldest lunar rocks are much older than any rocks found so far on Earth. Radiometric dating of lunar rocks has established an age range of 3.16-4.5 billion years. In contrast, the oldest Earth rocks dated so far are ~3.8 billion years. So why so old? Earth is a dynamic planet where the crust is continually being recycled which resets the radiometric clocks in rocks we date. Even though Earth is approximately 4.5 billion years old, those first rocks have long since undergone remelting and emerged as younger material. The Moon however is a 'dead' body. It's mass is too small to sustain a molten interior so the only recycling of crustal material since its formation has been volcanic eruptions early in its history and melting due to the shock of impacts. As a result, much of the lunar surface dates from its formation 4.5 billion years ago.
Lunar rocks are dry, very dry. Nearly all rocks on Earth contain volatile elements and compounds including water. Lunar rocks are strongly depleted in volatiles. These volatiles are tied up in the crystal structures of minerals that comprise lunar and terrestrial rocks. The extreme volatile depletion is not unique to lunar rocks but it is highly unusual for terrestrial rocks.
Lunar rocks are strongly depleted in the alkali elements sodium and potassium. Earth rocks are commonly enriched in these elements. Lunar rocks tend to resemble the most primitive or least differentiated rocks on Earth. While the most common rocks at Earth's surface are differentiated rocks enriched in volatiles and alkali elements, the most common rocks on the lunar surface are just the opposite. This is not only known from the lunar samples but from remote sensing of the lunar surface.
Lunar glass is far older than any natural glass found on Earth. Volcanic glass rapidly undergoes a tranformation to any number of minerals on Earth due to the presence of water which facilitates the chemical reactions. As a result, virtually all volcanic glass on Earth is very young, commonly less than a few tens of thousands of years old. Lunar glass can be billions of years old because there is no water on the Moon to participate in these chemical reactions.
Lunar regolith (soil) is enriched in He3 (a helium isotope)relative to virtually all Earth rocks and soils. He3 is a potential fuel for fusion power thus there is some thought to this as a fuel source for future lunar exploration and transportation.
Rocks from the lunar surface have been bombarded by cosmic radiation for billions of years and are somewhat worse for wear. The incidence of this intense radiation is well preserved by microscopic defects in the minerals that comprise the Apollo sample suite. Earth's atmosphere and the relatively young age of terrestrial rocks have prevented anything like the radiation damage seen in lunar samples.
Many but not all lunar rocks have no remnant magnetism. Remnant magnetism is created when molten rocks cool and iron bearing minerals form and align themselves parallel to a planetary magnetic field. The oldest lunar samples do indeed have remnant magnetism and this may indicate the Moon once had a magnetic field. Other lunar rocks have what may be 'shock' induced remnant magnetism induced by impacts to the lunar surface and local melting of the crust. Most lunar rocks have extremely weak or no remnant magnetism because the Moon does not have a magnetic field. I think it is safe to say that all terrestrial rocks have remnant magnetism which is induced by Earth's strong magnetic field.
There are many more diagnostic features of lunar rocks but the arguments become far more technical. The bottom line is virtually all educated people around the world believe the evidence of repeated Apollo landings. Americans can be rightfully proud that we had the will and technical ability to explore our nearest neighbor in the solar system. Those that are skeptical of this historic feat diminish the work and bravery of the thousands of people that carried out a risky but highly rewarding enterprise that has enriched all of our lives.
