Extraterrestrial UFO hypothesis

The extraterrestrial UFO hypothesis or extraterrestrial hypothesis (ETH), synonymous with interplanetary aircraft and alien UFO technologies, proposes that some unidentified flying objects (UFOs) are best explained as being physical spacecraft occupied by intelligent extraterrestrial organisms (non-human aliens) from other planets, or probes designed by extraterrestrials.

The scientific community has shown very little support for the ETH, and has largely accepted the explanation that reports of UFOs are the result of people misinterpreting common objects or phenomena, or are the work of hoaxers.