Time-traveler UFO hypothesis

The time-traveler hypothesis, also known as chrononaut UFO, future humans, extratempestrial model and Terminator theory is the proposal that unidentified flying objects are humans traveling from the future using advanced technology. Some notable people have given recent public exposure to the hypothesis, such as retired NASA aerospace engineer Larry Lemke, Wisconsin congressman Mike Gallagher, and American filmmaker Steven Spielberg.

Source: Wikipedia — Time-traveler UFO hypothesis (CC BY-SA 4.0)