Aliases
Disambiguation
NOT an official government classification. Term describes hypothetical craft or objects presumed to originate from other planets. Should not be confused with IFO (Identified Flying Objects) or official UAP/UFO taxonomy. Used descriptively in UFO/UAP literature to denote interplanetary origin hypothesis.
Stats
Concept
Hypothetical or theorized unidentified aerial objects presumed to originate from planets other than Earth; a descriptive category within extraterrestrial UFO hypothesis discourse rather than an official government classification.
Objetos aéreos não identificados hipotéticos ou teoricamente presumidos como originários de planetas diferentes da Terra; uma categoria descritiva dentro do discurso da hipótese UFO extraterrestre, e não uma classificação oficial do governo.
Enrichment
- Unidentified flying objectWikipedia▎ high· 2026-05-14
- UFO coined by USAF Captain Edward J. Ruppelt
- UAP first appeared in late 1960s, increased usage in 21st century
- Project Blue Book investigated 12,618 sightings (1952–1969); 701 remained unidentified
- Term 'flying saucer' emerged from 1947 Kenneth Arnold sighting
- The Army's Counter Intelligence Corps and UFOs: The Secret History of America's First UFO Investigators3i Atlas▎ medium· 2026-05-14
- Project Sign produced report in summer 1948 speculating about 'interplanetary' craft
- Air Force leadership rejected and destroyed report without evidence
- Army counterintelligence unit may have handled 'interplanetary phenomena' in late 1940s–1950s
- Records transferred to Air Force OSI in conjunction with Operation Blue Book
- CIA's Role in the Study of UFOs, 1947–90Federation of American Scientists▎ high· 2026-05-14
- Project SIGN, GRUDGE, and BLUE BOOK were primary Air Force UFO investigation programs
- No official evidence presented for extraterrestrial or interplanetary origins
- Robertson Panel concluded no evidence that objects sighted might be extraterrestrials
- Official terminology was UFO and flying saucer, not 'interplanetary' classification
INTERPLANETARY FLYING OBJECTS
Description (EN)
Stub generated by entity dedup. Will be enriched in Phase 6.
Descrição (PT-BR)
Stub gerado pela deduplicação de entidades. Será enriquecido na Fase 6.
<!-- enrichment:start -->Enrichment (EN)
Disambiguation: NOT an official government classification. Term describes hypothetical craft or objects presumed to originate from other planets. Should not be confused with IFO (Identified Flying Objects) or official UAP/UFO taxonomy. Used descriptively in UFO/UAP literature to denote interplanetary origin hypothesis.
Interplanetary Flying Objects (IFO) is a descriptive term referring to unidentified aerial phenomena theorized or hypothesized to originate from other planets or celestial bodies. The term emerged in early Cold War-era UFO investigations (late 1940s–1950s) as researchers and military officials considered extraterrestrial origins for unexplained sightings. It is distinct from the official acronym IFO (Identified Flying Objects) and from UFO (Unidentified Flying Objects). While the U.S. Air Force's Project Sign (1947–1949) produced internal reports speculating about 'interplanetary' craft, these were rejected by leadership without external release. The term represents a category within the broader extraterrestrial UFO hypothesis discourse rather than an official Pentagon classification. Modern government agencies have shifted away from language implying origin (such as 'interplanetary') in favor of neutral terminology: UAP (Unidentified Anomalous Phenomena).
Enriquecimento (PT-BR)
Desambiguação: NOT an official government classification. Term describes hypothetical craft or objects presumed to originate from other planets. Should not be confused with IFO (Identified Flying Objects) or official UAP/UFO taxonomy. Used descriptively in UFO/UAP literature to denote interplanetary origin hypothesis.
Interplanetary Flying Objects (IFO) é um termo descritivo referindo-se a fenômenos aéreos não identificados teoricamente originários de outros planetas ou corpos celestes. O termo emergiu durante investigações da Guerra Fria sobre UFOs (final dos anos 1940 e 1950) quando pesquisadores e oficiais militares consideravam origens extraterrestres para avistamentos inexplicáveis. É distinto do acrônimo oficial IFO (Identified Flying Objects) e de UFO (Unidentified Flying Objects). Embora o Projeto Sign da Força Aérea dos EUA (1947–1949) tenha produzido relatórios internos especulando sobre naves "interplanetárias", estes foram rejeitados pela liderança sem divulgação externa. O termo representa uma categoria dentro do discurso mais amplo da hipótese UFO extraterrestre, e não uma classificação oficial do Pentágono. Agências governamentais modernas abandonaram a linguagem que implica origem (como "interplanetária") em favor de terminologia neutra: UAP (Unidentified Anomalous Phenomena).
External Sources
- Unidentified flying object · Wikipedia · reliability:
high— UFO coined by USAF Captain Edward J. Ruppelt; UAP first appeared in late 1960s, increased usage in 21st century; Project Blue Book investigated 12,618 sightings (1952–1969); 701 remained unidentified; Term 'flying saucer' emerged from 1947 Kenneth Arnold sighting - The Army's Counter Intelligence Corps and UFOs: The Secret History of America's First UFO Investigators · 3i Atlas · reliability:
medium— Project Sign produced report in summer 1948 speculating about 'interplanetary' craft; Air Force leadership rejected and destroyed report without evidence; Army counterintelligence unit may have handled 'interplanetary phenomena' in late 1940s–1950s; Records transferred to Air Force OSI in conjunction with Operation Blue Book - CIA's Role in the Study of UFOs, 1947–90 · Federation of American Scientists · reliability:
high— Project SIGN, GRUDGE, and BLUE BOOK were primary Air Force UFO investigation programs; No official evidence presented for extraterrestrial or interplanetary origins; Robertson Panel concluded no evidence that objects sighted might be extraterrestrials; Official terminology was UFO and flying saucer, not 'interplanetary' classification