One of Apollo 11’s Finds.

Star Bound №23: I Was Wrong About Moon Rocks

Bruce McCandless III
9 min readMar 15, 2024


Reflecting on Fifty-Plus Years of Lunar Sample Science

We flew to the Moon to beat the Russians. We went to reclaim our technological throne, to avenge the sting of seeing Yuri Gagarin flying somewhere high over Cincinnati as the press fawned over Russian accomplishments and the world wondered if maybe communism held the key to cosmic progress.

Still, there had to be something we did on the moon other than planting the flag, something to talk about after we spent billions of dollars and put hundreds of thousands of Americans to work to ensure our low-gravity victory dance in July of 1969. What resulted in tangible terms was the fabled “moon rocks” toted back to Earth by the astronauts of Apollo — over 800 pounds worth of dust and rubble, the concrete evidence that we weren’t green with envy and geopolitical FOMO but in fact had Science in mind all along as we eyed the Soviets building their giant N-1 rocket.

And yet, as the moonglow faded, many Americans — including your trusty correspondent, then a skeptical and world weary eight-year-old — were left singularly unenthused about the lumpy gray collection of pebbles we’d beaten the Soviets to bring back from space. Moon rocks. Meh. The moon itself appeared to be sterile and monotonous, a weathered corpse adrift on cosmic tides. No wonder the nation’s interest in space exploration waned after the journeys of the Apollo astronauts. Certainly mine did. Skylab was next up on NASA’s agenda. I preferred to focus instead on Evel Knievel’s attempt to jump the Snake River in his steam-powered SkyCycle, a shambolic event that not only failed to advance human knowledge but may actually have set it back some.

Astronaut John Young Receiving Instruction from University of Texas Geologist Bill Muehlberger.

To be fair, just because boneheads like me couldn’t understand why it was important to bring home samples of another large object in the solar system, NASA — egged on by the National Academy of Sciences — apparently knew better. Beginning in 1964, the Apollo astronauts underwent hours of classroom study and geological fieldwork, including trips to the Grand Canyon, Texas’s Big Bend National Park, and the Newberry Caldera outside of Bend, Oregon in preparation for their missions. Some of them got to be pretty good rockhounds. Just to make sure the lunar landscape was getting sufficiently informed inspection, though, NASA eventually sent a pro. For 1972’s Apollo 17, the final Apollo mission, geologist Harrison (“Jack”) Schmitt was shoehorned into the capsule in place of hotshot pilot Joe Engle, the only man ever to barrel roll an X-15, the better to locate lunar loot in the Taurus-Littrow Valley.

Humanity’s collection of moon rocks consists mostly of the haul from America’s six successful Apollo missions, along with much smaller samples obtained from three Luna lunar probes launched by the Soviet Union in the 1970s and another robotic grabber, Chang’e 5, sent up by China in 2020. The term “rocks” suggests sizeable objects, but in fact the lunar surface is mostly regolith — broken rocks, dust, and gravel. This is because the moon gets a lot of abuse. As NASA geologist Sarah K. Noble puts it, “On the Earth, we have meteorites which impact on a regular basis, but smaller particles burn up in the atmosphere (shooting stars). On the Moon, everything impacts, down to the smallest micro and nanometer particles.” The result is lots of little pieces of rock, like busted-up shells on a wave-hammered beach. And because the little pieces aren’t weathered by water, they tend to be sharp. Lunar regolith clings to space suits, jams equipment, wears out whatever it touches. Regolith is a pain in the ass.

Astronaut Jim Irwin Takes in the Wonder of It All with Geologist Lee Silver.

Aside from what we’ve brought back from Up There, it turns out that there are also “natural” moon rocks littering Earth. These specimens were ejected from the moon at some period in the past, probably as a result of asteroid impact, and found their way through cislunar space and the blistering atmosphere of Earth to our surface. According to the Lunar and Planetary Institute’s Meteoritical Society, almost hundreds of lunar meteorites have been catalogued to date, most notably in unoccupied regions like Antarctica and Africa’s Sahara Desert. Interesting side note: Rocks from Earth have also been found on the moon. Indeed, scientists think the oldest Earth rock ever discovered is a piece of quartz, feldspar, and zircon picked up and brought back to Gaia by the astronauts of Apollo 14. The sample is believed to be some four billion years old. It must have gotten to the moon as a result of some violent impact, the same way moon rocks got here — although, because Earth’s gravitational pull is so much stronger than that of the moon, some six times as strong, it would have to have been a pretty horrific impact.

Several new minerals have been discovered in the rocks we’ve collected on space missions. Armalcolite, named after the men of the crew of Apollo 11, was the first, followed by pyroxoferroite and tranquillityite, each of which has since been found on Earth as well, or under it. The most recent new mineral find, changesite-Y, brought back by Chang’e 5, contains helium-3, sometimes called tritium, a hydrogen isotope that may someday be used to fuel nuclear fusion reactions.

Lunar samples have provided scientists with valuable information about how the Earth and the Moon came into existence. While astronomers use the Hubble and Webb Space Telescopes to gaze trillions of miles into the cosmos, searching for clues to our origins, some geologists have tried to trace the same story by looking deep into the chemical composition of our tiny trove of lunar samples. The results of their work have been astonishing — nothing short of a complete rewrite of the story of our corner of the galaxy. The easiest way to sum it up is to say that the similarity of moon rocks to our own terrestrial stones supports the theory that our planet and its opalescent satellite were created in their current form as a result of a cataclysmic collision between an “original” Earth, sometimes called Earth 1, and a Mars-sized body known as Theia.

Some 4.5 billion years ago, this collision basically destroyed both planets, which then slowly reformed during a geophysical gestational phenomenon known as “synestia,” a sort of placenta of swirling dust and gas and rock. Ever since, Earth and the moon, twin offspring of a turbulent birth, have performed an elaborate dance that affects our tides, our climate and seasons, our planetary rotation — which is stabilized on its axis by the gravitational pull of our closest neighbor — and even our magnetic field. Life on our planet evolved in rhythm with the phases of the moon, which many millions of years ago was much larger and much closer to our planet than it is now. Corals and other forms of aquatic life procreate in response to lunar stimuli. Birds and sea turtles navigate according to clues from the moon. Human menstrual cycles mirror lunar progressions.

In short, Earth would not be Earth without its pale sister, which got — from an anthropic perspective — a raw deal. Earth created an atmosphere for itself, thick enough to protect it from most asteroids. Earth grew forests, formed oceans, birthed plesiosaurs and flamenco dancers and Charles Bukowski. The moon, meanwhile, lost almost all of its atmosphere. It has been pelted for millennia by passing stones, from the giants that created the Tycho and Copernicus craters to much smaller objects that continue to sculpt the moonscape today. The near side of the moon — the side we see, as the moon is tidally locked to Earth in such a way that we always see the same side — is rough and somewhat mottled by impacts. And while the near side isn’t exactly pretty, the moon’s far side looks like the face of a carnival grifter, pockmarked and gruesome and vaguely menacing.

Pssst. Hey, kid. Wanna buy some zircon?”

Thanks to Extensive Training, Apollo’s Astronauts Knew a Rock When They Saw One.

Moon rocks have proven attractive over the years for their novelty as well as their scientific qualities. Richard Nixon sent Apollo 11 moon rocks — more like moon dust, really — to a number of nations and states in 1970. President Gerald Ford similarly sent out portions of the so-called Goodwill rock brought home by Apollo 17 to various nations. Unfortunately, many of these samples were lost or stolen, which eventually led to a concerted effort by former NASA investigator Joseph Gutheinz, and eventually his students, to figure out where the rocks went. Gutheinz’s efforts have resulted in a number of recoveries. Some of the samples were taken in garden variety thefts. Others ended up in private hands through circuitous routes, and the owners weren’t necessarily aware of what they had. According to New Science magazine, one sample had been “sitting in a box in the garage of a retired dentist.”

The odd attraction of moon rocks has inspired other crimes as well. One enterprising young Lothario, a NASA intern named Thad Roberts, stole some 100 grams of lunar and Mars material from a Johnson Space Center facility in 2002 and tried to sell it on the black market — but not before positioning the stuff under a mattress, or possibly a pillow, and then having “sex on the moon” with his lover. While the amount stolen may not sound like a lot, it was allegedly worth a substantial sum of money if it could in fact be sold. It was an expensive tryst, as Roberts later served six years in prison for leading the moon rocks heist and for his part in an unrelated crime involving the theft of dinosaur bones from the University of Utah.

It’s probably just as well that NASA didn’t emphasize the scientific goals of the Apollo missions. American taxpayers never would have shelled out for a series of flights to gather rocks that might — who knew? — yield insights into the origins of our planet and indeed of our solar system. Science isn’t that sexy. Racing the Russians was.

Plenty of intelligent observers continue to characterize NASA’s crewed space exploration missions as a front — a cover for America’s aggressive attempts to dominate space as the ultimate high ground. Apollo was a “technocratic stunt,” according to these folks, something shiny to wave in front of the rubes as we developed our digital satellite surveillance techniques.

This seems way too reductive to me. But even assuming that there’s a grain of truth to the space-as-new-battleground thesis, if the Apollo missions prove anything, it’s that even sideline science can yield momentous results. And the findings keep coming. In 2022, scientists at the University of Florida announced that they had managed to cultivate plants in lunar regolith, raising the possibility that astronauts might one day grow moon kale at their bases near the orb’s south pole — a prospect that has been hushed up for fear that it might dissuade thousands of grade-school vegetable haters from pursuing a future in STEM studies. Most of NASA’s moon rocks are kept in sterile, nitrogen gas-filled enclosures, but portions of the trove are available for study for anyone on the planet who can demonstrate a compelling scientific reason for the research. According to Dr. Barbara Cohen of NASA’s Goddard Space Center, the agency still receives something like a hundred requests per months from researchers eager for rocks to study. And the folks at Goddard are itching for more — rocks, that is, not requests. They are eager for the astronauts of NASA’s new Artemis program to bring back samples from the lunar south pole, with the region’s promise of polar ice and perhaps other surprises.

According to NASA, after America does an extended boot camp on the moon under the aegis of Artemis, we’ll set our sights on Mars. I can’t wait to see it happen. And despite my younger self’s dismissal of off-world geology, I’ll be the first to say it: Don’t forget to bring those sample return bags, folks!



Bruce McCandless III

I'm an Austin-based writer trying to figure out space, science, and Texas politics. For more, see: