From “On the Dangers of Lycanthropy and Lunar Exploration,” by Philip Plait, Astronecronomical Institute. Submitted to the Journal of Astronomy and Metaphysics; October 2023*

We are now very deep into the spooky season, with Halloween right around the corner. Not only that, but tomorrow night (October 28) is the full moon, so what better time is there to discuss the werewolf problem—or, as it’s known in the scientific literature, the lycanthropic principle?

We are all familiar with the lore. Werewolves transmogrify to lupine form during a full moon and crave the hunt, especially when humans are the prey. The details need not be delved into here. For further scholarly information, note Waggner, 1941, Landis, 1981, and, especially for the affliction in younger victims, Daniel, 1985.

Hypotheses abound on the scientific basis of the change, but unfortunately, empirical studies are few. (This is unsurprising, given the mortality rate for observers.) Medical journals occasionally publish speculative work on the biology of the lycanthropic transformation, but again, hard data are sparse. This problem is made worse by the fact that specimens obtained after death revert to human form, which irrevocably alters the DNA and biochemistry of any retrieved samples.

But here we will investigate the astronomical basis of the metamorphosis—specifically, the role of the moon—and then tackle its implications in the coming days of the Space Age. We are not proposing any specific solutions but merely wish to fire the imagination of other scientists to perhaps inspire them to pursue these matters further.

The moon is a rocky spherical body, approximately 3,474 kilometers in diameter. It orbits Earth at a distance of 384,000 kilometers on average and takes a little more than 27 days to do so. As it orbits, its “phase” changes; that is, the portion of it we see lit by the sun waxes and wanes over the course of a month. (The word “month,” we must note, is derived from the word “moon” because of the approximate period of the moon’s orbit.)

Because this is at the heart of the werewolf issue, let us take a moment to examine this phenomenon. The phase of the moon depends on geometry: the angle formed by the moon, the sun and Earth. When the moon is between our planet and the sun, we see the unlit side of it, the “night” side. We say at this time that the moon is new. A week later, when it has traveled approximately 90 degrees (one fourth) of the way around Earth, we see one half lit and one half dark. This is called the first quarter moon, in deference to its orbital position. Incidentally, the visible dividing line between day and night on the moon is called the terminator (see Cameron, 1984).

Similarly, two weeks after the first quarter, it is three fourths of the way around its orbit. We see it again half lit, but the formerly lit half is now dark, and vice versa. This is called third quarter. A week later it is new once again, and the cycle repeats.

Of course, of greatest concern to us is the phase when the moon is halfway around its orbit after it is new, opposite the sun in the sky. We see the lit half facing us with the entire hemisphere fully illuminated: hence, the full moon.

And herein lies the problem. We know this triggers the beastly conversion. It remains unclear, however, not only why but under exactly what circumstances the moon has this effect. To wit: Just how full must the moon be?

When we say the moon is full, in a strict sense, it isn’t. For that to be true, it would have to lie directly on a line with Earth between it and the sun, and when that happens, we get a total lunar eclipse! From the moon’s vantage point, Earth would block the sun, leaving the moon in Earth’s full shadow. Although we have no direct observations to verify the idea, popular lore suggests the werewolfian change only happens when the moon appears fully lit, which may exclude any effect during an eclipse.

So when we say the moon is full, it’s actually not exactly opposite the sun in the sky but offset by a small amount—generally speaking, a few degrees. This raises an immediate question: How far from totally full can the moon be and still trigger the werewolfification? Five degrees? Ten? By eye, the moon can appear quite full a day before and after it actually reaches that apex, when it is as much as 13 degrees away from opposition. This suggests an obvious experiment: measuring the exact time the human-to-werewolf change occurs and thus the exact phase of the moon.

There could be confounding factors. Do clouds affect the transformation? What if the victim is deep underground or encased in a lead-lined room—or, perhaps, on the opposite side of Earth when the moon is in the correct phase to trigger the lupinosity? Would they then transform only at moonrise, during twilight (Hardwicke, 2008) or later in the evening (Giacchino, 2022)? These factors would all need to be tested and weighted—leading, one hopes, to a better understanding of the major physical impetus of this change.

There is some urgency to uncovering these forces.

At this time, NASA, together with the European and Canadian space agencies, is already executing a program to return humans to the moon after a half-century gap in its exploration. This laudable goal comes with no small risk, but one simple threat is perhaps not taken seriously enough: What if someone on one of these flights is stricken with lycanthropy?

The odds of this are low but perhaps not zero. Only 24 humans were sent to orbit and land on the moon during the heady times of the Apollo missions; it’s a small sample, but still, we certainly dodged a (silver) bullet.

Collectively, NASA’s Artemis program and additional near-future lunar exploration plans from other nations could see many dozens more people sent. Were such efforts to spawn crewed circumlunar habitats or surface outposts, the number of humans around or on the moon at any given time could reach into the hundreds. The dangers of even one of them being a werewolf are so obvious they need not be expounded upon.

On the other hand, we don’t know if being literally in contact with the lunar surface would amplify the effects in unexpected ways or possibly negate them so entirely that they wouldn’t be an issue. We can conjecture that a werewolf transformation is caused by the moon as a body on the whole fully reflecting sunlight; being physically on it could mean the effects are minimized or nullified.

On the other paw, shortly after the monthly sunrise, the entire landscape surrounding our future lycanaut will be lit by the sun, which could then trigger the change; from their view, the entire moon would be illuminated, so it would be, by some definition, full. This could mean that the danger would be hugely amplified because the transformation wouldn’t last a mere terrestrial night but an entire lunar day, which is two weeks in duration. The carnage would be literally unearthly.

One shudders to think of what havoc might unfold upon a crewed space station in lunar orbit. A typical lunar satellite orbital height is 100 kilometers above the surface. Such an orbit would take approximately two hours, with, on average, nearly half of it over the unilluminated hemisphere, but obversely, that same amount of time would be spent over the sunlit half. This means that an afflicted human could change from human to monstrous canid and back again every two hours, staying in wolf form for a full hour at a time. In the enclosed volume of a small station, this would undoubtedly lead to mayhem.

Either on the lunar surface or above it, a transformation would certainly lead to a total loss of mission.

And what of Mars, to which NASA already has cast its eyes? Would our poor Martian astronaut suffer changes every time its moons are full? Is it possible that the phases of our planet’s moon affect them as well but at a reduced power because of the great distance, such that they only need to shave somewhat more aggressively and perhaps stifle cravings for rare steak?

One can only imagine the chaos of visiting Jupiter and Saturn, which have 95 and 146 confirmed moons at this time, respectively, and perhaps hundreds more yet to be discovered.

It is for this very reason that we put out this call to both the astronomical and biological communities. We must understand the lunar influence on the werewolf and also find some way to either block or stop it entirely. We should investigate the possibility of using silver-lined space capsules and the hydroponic cultivation of wolfsbane. I’m sure more potential modalities can be formulated as more scientists and space agency officials become aware of the urgent necessity.

There will come a day when we must take action, and we should be prepared. To reiterate Brooks, 1974, we do not want to answer the question “Werewolf?” by pointing at the moon and replying, “There, wolf.”

References

The Wolf Man. Directed by George Waggner. Universal Pictures, 1941.
Young Frankenstein. Directed by Mel Brooks. 20th Century Fox, 1974.
An American Werewolf in London. Directed by John Landis. Universal Pictures, 1981.
The Terminator. Directed by James Cameron. Orion Pictures, 1984.
Teen Wolf. Directed by Rod Daniel. Atlantic Releasing Corporation, 1985.
Twilight. Directed by Catherine Hardwicke. Summit Entertainment, 2008.
Werewolf by Night. Directed by Michael Giacchino. Marvel Studios, 2022.

*Editor’s Note (10/27/23): All scholarly information falls within the ghostly realm of fiction and Halloween fun.