The U.S. government has been inundated with hundreds of UFO encounter reports in the past year, and about half of them remain inexplicable, according to an unclassified document released by the Pentagon Thursday (Jan. 12).

The 11-page report, filed by the Office of the Director of National Intelligence (ODNI), reveals that the Pentagon has cataloged a total of 510 reports of alleged sightings of unidentified flying objects (UFOs) — or unidentified aerial phenomena (UAPs), as the government prefers to call them — largely filed by U.S. military personnel. Of these cases, 366 were newly identified in 2022, while the remaining 144 were identified in a prior ODNI report that looked at UFO data compiled between 2004 and 2017.

Of the 366 newly opened cases, 195 have been initially resolved with relatively mundane explanations; according to the report, 26 cases were identified as drones, 163 were classified as "balloons or balloon-like entities," and six were labeled as airborne clutter, such as birds or plastic bags. These findings fit with prior claims from Pentagon officials that most recent UAP reports were likely the results of foreign surveillance drones and clutter.

The remaining 171 cases are still "uncharacterized and unattributed," due to a lack of detailed data, according to the report. Some of these cases, which involved objects moving in unusual or inexplicable ways, remain under investigation.

The report declines to mention the possibility of alien involvement in any cases.

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However, it does state that "no encounters with UAP confirmed to contribute directly to adverse health-related effects to the observer" — contrary to a litany of questionable UAP reports released in 2022 claiming that some civilians suffered radiation burns, brain damage or "unaccounted for pregnancy" as a result of UFO encounters. (Those reports date as far back as 1873 and were not part of the Pentagon's recent investigations.)

The U.S. government has taken a renewed interest in UFO investigations over the past several years, ever since leaked military footage of several unidentified aircraft moving in seemingly impossible ways made its way to the mainstream media.

In early 2022, the Pentagon founded a new office specifically to coordinate and investigate UFO reports from U.S. military personnel. The office, called the All-domain Anomaly Resolution Office, has taken charge of the 366 newly identified reports and expects to receive many more as the government works to destigmatize UAP reporting in the interest of national security, agency officials said.