On October 13, 1917, somewhere between 30,000 and 100,000 people gathered in a muddy field in Fátima, Portugal, after three shepherd children predicted the Virgin Mary would perform a miracle there, and according to a huge number of witnesses, including skeptical journalists from anti-clerical newspapers, the sun itself appeared to spin, change color, and plunge toward the earth before returning to its normal position. More than a century later, the event remains genuinely, unusually contested: proposed scientific explanations exist, but so do specific details that those explanations struggle to fully account for, making Fátima one of the few cases in this series where researchers on very different sides of the question agree the standard mass psychogenic illness label may not cleanly apply.
Background: Three Children, a Promised Sign, and a Skeptical Press
Beginning in May 1917, three young shepherds, ten-year-old Lúcia Santos and her cousins Francisco and Jacinta Marto, reported a series of apparitions of the Virgin Mary near their village of Fátima. According to their accounts, the Virgin promised that on October 13, she would perform a public miracle so that "all may believe." The children faced considerable skepticism, mockery, and even brief detention by local authorities in the months leading up to the promised date, yet maintained their story consistently.
News of the prophecy spread widely enough that, despite World War I straining transportation and communication across Portugal, tens of thousands of people, including openly skeptical secular journalists from anti-clerical newspapers like O Século, made the journey to the rural Cova da Iria on the appointed day, arriving into a field soaked by heavy overnight rain.
What Witnesses Reported Seeing
Around midday, accounts describe the clouds parting to reveal a sun that appeared, to the assembled crowd, as a spinning silvery disc that could be looked at directly without pain, unlike the ordinary sun. Witnesses described it changing colors, rotating like a wheel, and at points appearing to zigzag or plunge toward the crowd before retreating, producing what many present described as terror followed by relief once the sun apparently returned to normal. Some accounts, including from witnesses initially skeptical of the prophecy, additionally reported that ground and clothing soaked from the earlier rain appeared dry within minutes of the event ending.
Crucially, and unusually for a claimed mass phenomenon, reports emerged from observers as far as roughly 11 miles away who described seeing unusual solar activity at the same time, and not everyone present at Cova da Iria itself reported seeing the same phenomenon, some in the crowd reported seeing nothing unusual at all.
Fátima Compared to Clearer Cases in This Series
| Case | Year | Nature of the Event | Fits Standard MPI Pattern? | Level of Scientific Consensus |
|---|---|---|---|---|
| Miracle of the Sun, Fátima | 1917 | Predicted, sudden, brief visual phenomenon | Disputed; lacks gradual spread and physical symptoms typical of MPI | Genuinely contested among researchers |
| Tanganyika Laughter Epidemic | 1962 | Gradual, spreading physical symptoms | Strong fit | Well-supported consensus |
| Blackburn Fainting Epidemic | 1965 | Rapid onset, spreading physical symptoms | Strong fit | Well-supported consensus |
| "Toxic Lady" (Gloria Ramirez) | 1994 | Sudden onset, single triggering event | Partial; competing chemical evidence | Genuinely contested |
Theories & Explanations: Why the Usual Categories Don't Fit Cleanly
The leading naturalistic explanation involves the eyes, not the sky. Several researchers, including science writer and skeptic Joe Nickell, have proposed that prolonged, direct staring at the sun caused solar retinopathy, temporary damage and afterimages on the retina, combined with expectation and suggestion within a highly emotional crowd, a documented phenomenon in other cases of large groups staring at the sun during religious observances.
But that explanation has real gaps its proponents acknowledge. Solar retinopathy is an individual, subjective effect, and researchers examining Fátima specifically note it struggles to explain why witnesses separated by many miles, who could not have been influenced by the same crowd or the same suggestion, reported broadly similar phenomena at the same time, or why some people in the same crowd saw nothing unusual at all.
Standard mass psychogenic illness doesn't map cleanly onto the event's shape. Researchers who study MPI, including Skeptical Inquirer's own analysis of the case, have noted that classic mass psychogenic illness typically involves a gradual spread of physical symptoms, headaches, fainting, nausea, through a group over time, not a single, brief, predicted, and collectively witnessed visual event with an abrupt beginning and end, making Fátima a genuinely awkward fit for the category even among researchers skeptical of a supernatural explanation.
Alternative naturalistic theories exist but remain unproven. Proposals including atmospheric optical effects from ice crystals or dust, and even a 1989 Journal of Meteorology hypothesis involving stratospheric dust, have been offered over the decades, though none has achieved anything close to consensus acceptance as a complete explanation for every reported detail.
The Curious Connection
Fátima earns its place in this series less as a confirmed case of mass psychogenic illness than as a genuine edge case that tests the category's limits, alongside the Toxic Lady and Havana Syndrome cases covered earlier. What makes it distinct even from those is the specific mismatch between the event's structure, sudden, predicted, brief, and partly witnessed at a distance, and the gradual, symptom-based spread that defines most confirmed cases throughout this series.
Whether the explanation ultimately lies in retinal science, crowd psychology, atmospheric optics, or something the standard toolkit hasn't fully captured, Fátima remains a useful reminder that not every mass phenomenon fits neatly into the frameworks researchers have built to study them, and that intellectual honesty sometimes means acknowledging a case doesn't resolve as cleanly as the rest.
Frequently Asked Questions
How many people witnessed the Miracle of the Sun?
Estimates vary widely, with figures ranging from roughly 30,000 to 100,000 people gathered at Cova da Iria near Fátima, Portugal on October 13, 1917, including both religious believers and openly skeptical journalists.
Is solar retinopathy a complete explanation?
It's the leading naturalistic proposal, but even researchers who favor it acknowledge it doesn't easily explain reports from witnesses many miles away who couldn't have been influenced by the crowd at Cova da Iria, or why some people present reported seeing nothing unusual.
Does this count as mass psychogenic illness?
It's genuinely disputed. Researchers who study MPI note the event's structure, a predicted, sudden, brief visual phenomenon rather than a gradual spread of physical symptoms, doesn't cleanly match the pattern seen in most confirmed cases.
What do religious sources say about the mass hysteria explanation?
Investigators sympathetic to the apparitions, including canon lawyer José Maria de Almeida Garrett and later commentators, have argued the varied religious backgrounds of witnesses, the distant sightings, and the lack of an identified physical cause make mass hallucination an unlikely complete explanation.
Has any single explanation achieved scientific consensus?
No. Proposed explanations, including solar retinopathy, atmospheric optics, and stratospheric dust, remain competing hypotheses rather than an agreed-upon conclusion, making Fátima one of the more genuinely unresolved cases examined in this series.