UAP Codex · open research

79 years without an official explanation.

There's something institutions couldn't — or wouldn't — explain since 1947. A compendium of the 339 best-documented institutional cases — the ones that survived military, congressional, and journalistic filters. Not a sightings list. The evidence that doesn't explain away easily.

Explore the 339 casesHow likely each explanation is
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The scope

It's not theory — it's a documented evidence collection.

339

Institutional cases

Plus 81 official documents that back them

79

Years of phenomenon

Longer than the entire Cold War (1947–1991)

73

Countries with records

Every continent except Antarctica — not a US-only phenomenon

See the global map · 73 countries →

The corpus answer — in one sentence and in numbers

UAP are not one single thing. They are several distinct things mixed under the same label — and that's exactly what makes them hard to explain.

Most point to classified military programs — we've known since the U-2 (1950s) and the F-117 (1980s). A non-trivial portion involves non-human entities we don't yet know how to categorize. Some may be rare natural phenomena (plasma, sprites), though multi-sensor military evidence rules that out for most Tier S cases. Misidentifications get filtered out first — what remains are the 339 cases that survived that culling.

How the corpus's 339 incidents classify among the narratives — they sum to 100%

Aeronave: 18.9%Sin explicación propuesta: 18.3%Objeto astronómico: 9.4%Posible fraude: 8.0%Objeto espacial: 7.7%Indeterminado: 7.4%Fenómeno natural: 7.4%Causa psicológica, médica o social: 5.3%En tierra: 5.0%Tecnología adversaria: 3.5%Animal: 3.2%No-humano: 2.1%Tecnología humana clasificada: 1.8%Fallo de instrumento: 1.5%Relato folclórico o literario: 0.6%18.9%18.3%9.4%8.0%7.7%7.4%7.4%
339cases
  1. Aircraft18.9% · 64 cases
  2. No explanation proposed18.3% · 62 cases
  3. Astronomical object9.4% · 32 cases
  4. Possible hoax8.0% · 27 cases
  5. Space object7.7% · 26 cases
  6. Indeterminate7.4% · 25 cases
  7. Natural phenomenon7.4% · 25 cases
  8. Psychological, medical or social cause5.3% · 18 cases
  9. Ground-level5.0% · 17 cases
  10. Adversary technology3.5% · 12 cases
  11. Animal3.2% · 11 cases
  12. Non-human2.1% · 7 cases
  13. Classified human technology1.8% · 6 cases
  14. Instrument artifact1.5% · 5 cases
  15. Folklore or literary account0.6% · 2 cases

Forced, navigable classification — each incident counts once in its most-likely narrative (argmax); the prosaic is named by what it was —object classes, natural phenomenon, possible hoax—, non-human consolidated. Documents do not count: they are evidence, not events. 'Indeterminate' gathers what cannot be decided. The expected-value split —comparable, spreading the uncertainty— is on /calidad.

How the corpus splits among the explanations →

Temporal distribution

Reports don't distribute randomly.
Four peaks mark institutional ruptures.

1947 Roswell — USAF creates Project Sign · 1973 Pascagoula — Senate hearings · 2004 Nimitz — first official ATFLIR video · 2026 PURSUE — first presidential disclosure. Each peak is a moment when an institution could no longer keep denying.

Corpus por año · 1947–2026

339 casos · 79 años

46

1950s

52

1960s

52

1970s

31

1980s

27

1990s

20

2000s

30

2010s

52

2020s

Walk the 339 cases chronologically →