Tradition 20 of 33
UFOs, extraterrestrials, and contact
UFO/UAP reports, flying saucers, extraterrestrial life, alien contact or abduction, contactees, and ancient-astronaut claims.
Membership means relevance, not endorsement.
- Books
- 1,058
- Earliest
- 1558
- to 2026
- Read free
- 22%
- 236 with public full text
- With covers
- 58%
How books qualify
- Query + metadata match981
- Metadata match69
- Query match7
- Source classification (retained through merging)1
Every placement records its evidence — the controlled subject queries that found the book at its sources and the bibliographic metadata retained through merging. Each book page shows its own. How the rationale system works.
Key subjects
- Fiction324
- Science fiction258
- Extraterrestrial beings247
- Human-alien encounters220
- Unidentified flying objects204
- UFO128
- Alien abduction101
- Short Stories92
- Physical Sciences86
- Social Sciences83
- Astronomy and Astrophysics82
- Physics and Astronomy82
- Life on other planets81
- Children's fiction80
- Sightings and encounters79
- Space Science and Extraterrestrial Life78
- Fiction, science fiction, general77
- Juvenile fiction74
- History69
- Philosophy68
- Psychology68
- Extraterrestrial beings, fiction62
- Social Psychology52
- 未確認飛行物体46
Top languages
- English771 · 73%
- German85 · 8%
- Japanese48 · 5%
- French31 · 3%
- Dutch29 · 3%
Notable authors
All authors- Jacques Vallee14 in this tradition15 books
- Katherine Applegate12 books
- M. de Fontenelle11 in this tradition12 books
- Bernard Le Bovier de Fontenelle9 in this tradition15 books
- Virgil Finlay8 in this tradition12 books
- Ed Emshwiller7 in this tradition11 books
- George Adamski7 books
- Orson Scott Card6 in this tradition8 books
- Pittacus Lore6 in this tradition7 books
- Donald E. Keyhoe6 books
- Marissa Meyer6 books
- Robert A. Heinlein6 books
1,058 books
Children of Time
Adrian Tchaikovsky
2015
- Read free
Observations philosophiques sur les systèmes de Newton, le mouvement de la terre et la pluralité des mondes. Dialogues des morts sur le séjour des vivants, avec une dissertation sur les tremblements de terre, les épidémies, les orages, les inondations. Par M. l'abbé Flexier de Réval
Franc̜ois Xavier de Feller
1778French
Moderner Mythus
Carl Gustav Jung
1959
Eon
Greg Bear
1985
- Read free
La pluralité des mondes , par feu Mr. Hughens,... traduit du latin en françois par M. D***
Christiaan Huygens
1702French
Stranger in a Strange Land
Robert A. Heinlein
1961
The UFO experience
J. Allen Hynek
1972
Starship down
Justin Giampaoli
2020
Death's End (The Three-Body Problem Series Book 3)
刘慈欣
2010
Decision at Doona
Anne McCaffrey
1969
Alien Agenda
Jim Marrs
1997
The siege of eternity
Frederik Pohl
1997
- Read free
Extraterrestrial Life
Antonino Del Popolo
2025
Extraterrestrial Visitations
Preston E. Dennett
2001
Flying saucers have landed
Desmond Leslie, D & Adamski Leslie, George Adamski
1953
- Read free
Lettres à un matérialiste sur la pluralité des mondes habités et les questions qui s'y rattachent (3e éd.)
Jules Boiteux
1898French
- Read free
Tom Swift and The Visitor from Planet X
Victor Appleton, Graham Kaye
Date unknown
- Read free
Venus Boy
Lee Sutton, Richard Floethe
Date unknown
A Memory Called Empire
Arkady Martine
2019
Hyperion
Dan Simmons
1989
Hair of the Alien
Bill Chalker
2005
- Read free
Les astres et la pluralité des mondes
Adrien Beuque
1868French
Planet of the Damned
Harry Harrison
1900
The Demon-Haunted World
Carl Sagan
1995