The Moon is the Pits
The National Aeronautics and Space Administration (NASA) emphatically dismisses suggestions that our Moon is less-than-solid—yet initiatives funded by the space agency point to a continued interest regarding the makeup of its interior. The routine discovery of hundreds of skylights on the lunar surface (openings in the Moon that expose cavernous tunnels below) has recently prompted NASA to sponsor the development of robotic mini-rovers designed to image and explore the off-world fissures.
A study in the October 2020 volume of Earth-Science Reviews calculated the dimensions of these enormous lunar cavities. Their findings reveal that a fair number of these underground tubes are hundreds of times bigger than any seen on Earth. According to the study’s lead, one of the moon’s larger tunnels “could easily contain a small city within its walls.”
Taken together, these developments have rekindled speculation about the Moon’s true composition and internal structure.
Beyond the imaginative scenes generated by early-1900’s sci-fi writers, the idea that Earth’s nearest space-neighbor might be empty has had its share of adherents over the years. The modern ‘Hollow Moon Theory’ traces part of its origin to a book published in 1966 by prominent astronomer Carl Sagan and Russian astrophysicist I.S. Shklovskii. Their literary product, Intelligent Life in the Universe, contained a chapter about the curious nature of the moons orbiting Mars—Phobos and Deimos. Based on their calculations, the objects had an abnormally low density, spurring them to beg the question: Could they be “rigid on the outside—but hollow on the inside?” The authors wondered if an advanced Martian civilization might’ve created the artificial satellites to act as low-gravity platforms. This orbital arrangement would’ve allowed them to launch deep-space missions more easily—an advantage that Earth’s moon also provides.
Nice ‘one-eye’ symbolism on the cover, Carl!The grandfather of NASA’s rocket program, Dr. Werner Von Braun, unwittingly fueled the hollow Moon legend with an article he penned for Popular Mechanics about the Apollo 13 mission’s plan to crash a 15-ton portion of the Saturn V rocket into the lunar surface. The experiment was a follow-up to the deliberate dropping of Apollo 12’s Lunar Module, the impact of which caused the Moon to “ring like a bell for nearly an hour, indicating some strange and unearthly underground structure.”
Despite Apollo 13’s ultimate failure to land on the Moon, they were able to deliver their payload for the experiment, yielding similar lunar-shaking results as the prior collision. Mission Control notified the Apollo 13 crew of their success: “Looks like your booster just hit the moon, and it's rocking it a little bit.” The suggestive phrasing has provided fodder for fringe theorists who claim that the Moon might be mostly hollow.
Building off of Sagan’s earlier meditations about the nature of the Martian moons, two Russian scientists, Vasin and Shcherbakov, surmised that the peculiarities plaguing the Moon could be resolved with a creative explanation: Earth’s orbiter is an artificial, hollowed-out object turned sputnik that was purposefully placed near our planet by a highly advanced extraterrestrial culture. The Soviet duo published their thoughts on the matter in a 1970 piece titled, “Is the Moon the Creation of Alien Intelligence?” Their circumstantial conjectures about an alien-engineered satellite paved the way for what became known as ‘The Spaceship Moon Hypothesis.’
One of the first to pick up the thread was researcher and author, Don Wilson. He summarized his hypothesis about a fabricated satellite circling Earth in a pair of books—Our Mysterious Spaceship Moon (1975), and Secrets of Our Spaceship Moon (1979). Wilson cited anomalies like the shallowness of lunar craters (a sturdy hull protecting the moon-ship doesn’t allow meteors to penetrate deeply), and the presence of strange structures and lights littering the surface (evidence of artificial vehicles and navigation markers) as proof that the Moon wasn’t formed naturally.
Heavily inspired by Vasin and Shcherbakov’s “Soviet spaceship theory,” Wilson agreed that the Moon was likely an antique alien space-shuttle. This required that it be a mostly-hollow vehicle—especially when considering the size of his proposed cargo: “The huge spaceship carried everything necessary to serve as a kind of Noah’s Ark of intelligent creatures on a voyage through the universe.”
Interestingly, Wilson referenced the existence of lunar features that sound similar to skylights. He mentioned the work of amateur astronomer Dr. H. P. Wilkins, who was convinced that “extensive hollow areas did exist inside the Moon, perhaps in the form of caverns, and that these were connected to the surface by huge holes or pits.” Wilson speculated that these ‘pits’ were possibly entrances to “underground, hidden bases located inside the Moon.”
Another book written in the same vein as Wilson’s was assembled by Christopher Knight and Alan Butler. In Who Built the Moon? (2005), the authors note many “outrageous coincidences” between the Moon, Sun, and Earth (like the precise dimensions required for the Moon to produce a solar eclipse or regulate Earth’s tides) and insist our planet’s companion was intentionally put in place. Unlike Wilson’s conclusion that the Moon was a “cosmic Noah’s Ark” that had been piloted to its current location from outside our solar system, Butler & Knight theorized that it was manufactured by Earthly architects using the planet’s available elements. (This is allegedly why tests of lunar surface material revealed their composition to be extremely similar to Earth’s.)
As to who held the blueprints for the artificial Moon—Knight elaborated on three possibilities in an interview with New Dawn Magazine:
“God, aliens or humans. The only one of these that is 100% scientifically possible is the last one. Time travel is universally accepted as being physically possible and a number of scientists are close to sending matter back in time. We can envisage that machines could be built in the future that could be sent back to remove matter from the young Earth to construct the Moon – probably using mini black hole technology.”
Who Built the Moon? We did. By using time machines from our distant future…one that never would’ve existed if we didn’t have the Moon in the first place.Some of the mysteries surrounding the Moon’s formation may eventually be answered by investments in rugged autonomous robots. New rovers are being developed specifically for subsurface exploration of the dark lunar crevices. Today’s prototypes are capable of repelling down yawning extraterrestrial maws, and come loaded with high-resolution imaging equipment.
One front-running model was tested at a terrestrial sinkhole in Utah in preparation for a future Moon-shot. Dubbed the PitRanger by its creators at Carnegie Mellon University, the unmanned lunar vehicle is built to gather photos of a skylight from multiple angles and gain a comprehensive picture of the situation on the ground. Obtaining a closer view of these subterranean portals could dramatically advance our understanding of the Moon’s layout. With luck, some of these rovers could be deployed as soon as 2022, and should be seriously considered as part of NASA’s Artemis Moon missions.
It might not be a hollowed-out ancient alien spaceship, but the Moon’s origins are still scientifically unsettled. It makes sense that a focused effort is taking place to get to the bottom of off-planet pits—not only for their base-building value—but also for the treasure trove of data they likely hold about how bodies in our solar system were formed. If the soon-to-be explored lunar passages extend far beneath the surface, they could help explain some of the Moon’s oft-reported anomalies while providing access to secrets buried beneath the regolith.
As their increased interest in pit-diving robots and lunar exploration suggests—even if theories involving a hollow Moon don’t strike a chord with NASA officials, they do ring a bell.
