UFO

Alien

coming from another world

UFO

a mysterious flying object in the sky that is sometimes assumed to be a spaceship from another planet: unidentified flying object

Extraterrestrial life

originating, existing, or occurring outside the earth or its atmosphere

Civilization

a relatively high level of cultural and technological development

Interstellar travel

located, taking place, or traveling among the stars especially of the Milky Way galaxy

Exoplanet

a planet orbiting a star that is not our sun

Conspiracy theory

a theory that explains an event or set of circumstances as the result of a secret plot by usually powerful conspirators

Government cover-up

a usually concerted effort to keep an illegal or unethical act or situation from being made public

Alien abduction

the action of abducting: the condition of being abducted

Close encounter

a chance meeting

Crop circles

a geometric and especially a circular pattern of flattened stalks in a field of grain now usually attributed to natural phenomena or to the work of hoaxers trying to create the impression of a visit by extraterrestrial beings

Hoax

to trick into believing or accepting as genuine something false and often preposterous

Evidence

something that furnishes proof

Debunker

Believer

Someone who accepts something as true, genuine, or real

Skeptic

a person disposed to skepticism especially regarding religion or religious principles

Hostile

marked by malevolence : having or showing unfriendly feelings

Peaceful

untroubled by conflict, agitation, or commotion