No credible evidence exists that U.S. authorities covered up extraterrestrial life, in the form of unidentified flying objects, even if some Americans firmly believe in UFOs, a Pentagon report said Friday.

The report offered a number of explanations of what has led to more than 40% of Americans thinking that life forms from another galaxy have visited earth.

“Investigative efforts determined that most sightings were the result of misidentification of ordinary objects and phenomena,” according to the conclusion of a 63-page report on “unidentified anomalous phenomena (UAP).”

“Although many UAP reports remain unsolved, AARO (All-domain Anomaly Resolution Office) assesses that if additional, quality data were available, most of these cases also could be identified and resolved as ordinary objects or phenomena.”

The report listed several satellite and other data-gathering craft developed, usually in secret, by the government and private industry that could have easily been identified as UFOs by the general public.

“The below examples represent a sample of the unclassified and declassified authentic national security programs that AARO assesses probably were associated with erroneous UAP reporting,” it said of crafts built by companies such as Lockheed Martin and Northrop Grumman.

The report suggested that Americans’ belief in UFOs is unlikely to change.

“Aside from hoaxes and forgeries, misinformation and disinformation is more prevalent and easier to disseminate now than ever before, especially with today’s advanced photo, video, and computer generated imagery tools,” the report said. “Internet search and content recommendation algorithms serve to reinforce individuals’ preconceptions and confirmation biases just as much as to help educate and inform.”

This article was originally published on NBCNews.com