June 26 (UPI) -- A highly anticipated U.S. government report on UFO sightings has concluded there's not enough data to conclusively explain them, but also did not rule out they may be of extraterrestrial origin.
The nine-page report released by the Office of the Director of National Intelligence on Friday found that there isn't enough information to draw conclusions about 143 of 144 reports of "unidentified aerial phenomena" submitted by government sources between 2004 and 2021, mainly by pilots on military training missions.
The single UAP that was explained turned out to be a large, deflating balloon, while "the others remain unexplained," according to the report, which was commissioned by Congress.
The report confirmed what it called "unusual" UAP activity on multiple occasions, and in those cases it did not rule out the possibility they have could have been caused by "sensor errors, spoofing, or observer misperception.
Those incidents, it said, require "rigorous" further analysis.
What limited data the government does have supports the idea that "if and when individual UAP incidents are resolved they will fall into one of five potential explanatory categories: airborne clutter, natural atmospheric phenomena, [U.S. government] or U.S. industry developmental programs, foreign adversary systems, and a catchall 'other' bin."
The report makes no mention of alien visitors, but neither does is specifically rule out the possibility of extraterrestrial origin of UAPs, admitting that some of the observed incidents may be beyond the ability of the government to explain.
A "handful" of the UAP incidents "appear to demonstrate advanced technology," it said.
In 18 incidents, observers reported seeing unusual movement patterns or flight characteristics, such as appearing to remain stationary in winds aloft, moving against the wind, maneuvering abruptly or moving "at considerable speed, without discernable means of propulsion."
In a few cases, the report said, military aircraft detected radio frequency energy associated with the UAP sightings.
"We have no clear indications that there is any non-terrestrial explanation for them, but we will go wherever the data takes us," an unnamed senior U.S. government official told NBC News.