Sept. 9 (UPI) -- The existence of extraterrestrial flying objects is one of the longest enduring conspiracy theories in history, and a new survey shows that almost two-thirds of Americans believe the federal government knows more than it's saying on the matter.
Gallup said researchers discovered 68 percent of respondents answered "yes" when asked whether the U.S. government knows "more about UFOs than it is telling us." Twenty-nine percent said "no." Of those who answered "yes," about half also said they believe the government is hiding information about alien space landings.
Thirty-three percent said they believe an alien spacecraft has visited Earth at some point.
The survey results continue a decades-long trend of distrust among Americans for their government on the subject of intelligent alien life. Gallup's 1996 survey on the issue showed 71 percent didn't trust the government on the issue.
Perhaps no other event has been linked to government involvement than a crash in Roswell, New Mexico, in July 1947. A number of witnesses claim to have seen the wreckage of an alien spacecraft there, and the U.S. military hauling the debris away. The government has long denied the claims, saying at the time the wreckage belonged to a downed weather balloon.
As for UFO sightings, Gallup found 60 percent were skeptical, saying they can be explained by human activity or natural phenomenon. Only 16 percent said they have personally witnessed something they thought was a UFO -- while the majority (84 percent) have not. Thirty-three percent said at least some of the UFO sightings throughout history were actual alien spacecraft.
"Regardless of what Americans think of UFOs or the government's awareness of them, the subject is part of the nation's consciousness with 86 percent of U.S. adults saying they have heard of or read about unidentified flying objects," Gallup said.
Gallup conducted polling on the subject between June and August.