xenobiology
xenoscience
xenopaleontology
xenobiochemistry
xenomorphology
alien
xenoengineering
xenotechnology
exocommunication
xenology
exogenesis
extraterrestrialization
UFO
flying saucer
unidentified flying object
xenocytology
astrobiology
xenomicrobiology
xenogeology
xenophysics
exobiology
space biology
bug-eyed monster
xenochemistry
benthophil
benthic
eetee
extraterrestriality
xenobacteriology
space invader
ghost
space alien
bolide
alienkind
xenomorph
visitor
xenopsychology
xenoanthropology
alienism
xenozoology
astrozoology
entity
substar
xenoethics
ayy
parabiosis
paleocontact hypothesis
ancient astronaut hypothesis
xenoarchaeology
extraterrestrialness