A review by the U.S. Defense Department of its own interest in UFOs concludes that it hasn't found or covered up any evidence of aliens.
From the report, Report on the Historical Record of U.S. Government Involvement with Unidentified Anomalous Phenomena [PDF]:
To date, AARO has not discovered any empirical evidence that any sighting of a UAP represented off-world technology or the existence a classified program that had not been properly reported to Congress. Investigative efforts determined that most sightings were the result of misidentification of ordinary objects and phenomena. Although many UAP reports remain unsolved, AARO assesses that if additional, quality data were available, most of these cases also could be identified and resolved as ordinary objects or phenomena.
Maj. Gen. Patrick Ryder, quoted in the New York Times:
Ryder, a Defense Department spokesman, said the Pentagon approached the report with an open mind and no preconceived notions, but simply found no evidence to back up claims of secret programs, hidden alien technology or anything else extraterrestrial.
"All investigative efforts, at all levels of classification, concluded that most sightings were ordinary objects and phenomena and the result of misidentification," General Ryder said in a statement.
While many reports of what the government now calls Unidentified Anomalous Phenomena remain unsolved, the new document states plainly there is nothing to see. The Pentagon's All-domain Anomaly Resolution Office concluded that if better quality data were available, "most of these cases also could be identified and resolved as ordinary objects or phenomena."
Is this gonna be a standup fight, sir, or another bug hunt?
Previously: Portable UFO detection kit in development by US military