A highly anticipated report on UFOs, prepared by the U.S. intelligence community and delivered to Congress on Friday, does not provide definitive explanations for 143 encounters the U.S. military reported with unidentified aerial phenomena, or UAPs, that took place between 2004 and 2021.
An unclassified version of the report, released on the Office of the Director of National Intelligence website, does not contain the words "alien" or "extraterrestrial" and says further study or "pending scientific advances" may be needed to help explain what are known as unexplained aerial phenomena or UAP's that fall into a vague category the report lists as "other."
But a senior U.S. government official did not rule out the possibility that future data may lead to non-Earth-related technologies.
"Of the 144 reports we are dealing with here, we have no clear indications that there is any non-terrestrial explanation for them - but we will go wherever the data takes us," said a senior U.S. government official, who also noted that they did not show that a foreign adversary had made significant technological leaps.
"We are open to other hypotheses that is meant to recognize that we have many things that we are currently unexplained," said the official. "We are open to the possibility that some things may be unexplainable with our current level of understanding."
The seven-page report presented to congressional committees on Friday met a requirement Congress put in place last year requesting that the U.S. intelligence community take six months to prepare an unclassified and classified report on what the U.S. government knew about UAP's.
"The limited amount of high-quality reporting on unidentified aerial phenomena (UAP) hampers our ability to draw firm conclusions about the nature or intent of UAP," said the report.
"The UAP documented in this limited dataset demonstrate an array of aerial behaviors, reinforcing the possibility there are multiple types of UAP requiring different explanations," the report said.
The report reviewed 144 UAP incidents reported by U.S. military personnel in recent years. Only one could be explained and was attributed to a large deflating balloon.
The report detailed that there was not enough data gathered from the remaining 143 incidents to provide explanations as to what was described, but it lists five hypotheses that may possibly explain some of them in the future.
Those categories include "airborne clutter" -- a reference to birds, balloons, or drones in the atmosphere -- natural atmospheric phenomena like ice crystals that may be present on sensors, U.S. government or industry developmental programs, systems from a foreign adversary, and the catch-all category listed as "other."
"Most of the UAP reported probably do represent physical objects given that a majority of UAP were registered across multiple sensors, to include radar, infrared, electro-optical, weapon seekers, and visual observation," the report said.
But another senior U.S. government official acknowledged that some of the UAP incidents described in the report were "an array of aerial behaviors" that indicate that "that not all UAP are the same thing, there is a wide, wide range of phenomena that we observe."
"There is not one single explanation for UAPs, it's rather a series of things," said the official. "And our analytic approach to this is to create a framework in which we have considered five explanatory categories that we believe are plausible explanations for a UAP that we observe."
The report cited 18 incidents "that appear to demonstrate advanced technology" based on flight characteristics. In those incidents, UAP "appeared to remain stationary in winds aloft, move against the wind, maneuver abruptly, or move at considerable speed, without discernible means of propulsion."
"In a small number of cases, military aircraft systems processed radio frequency (RF) energy associated with UAP sightings," it added.
"There are 18 incidents in the database, in the data that we're working with, in which the UAP do appear to have some sort of propulsion or other technologies that's not immediately evident, that could be advanced," said the U.S. government official.
The official noted that the propulsion is noted less in high-speed incidents, but in "station keeping against the wind" where "we don't have clear indications of what's the propulsion that's being used for that."
As for some of the incidents captured on video, the official said some are "propulsion that we can't explain" though in some cases objects that appeared to be moving fast "may not be moving as quickly as it appears that they are in that video."
With the need for more data to analyze UAPs, the Pentagon announced new steps designed to standardize reporting and analysis of UAP reports across the military.
The report said the Pentagon's UAP Task Force has begun to receive additional data from the Federal Aviation Administration from civilian pilots reporting "unusual or unexpected events."
"This report is an important first step in cataloging these incidents, but it is just a first step," said Sen. Marco Rubio, R-Fla., the former chairman of the Senate Select Committee on Intelligence who championed the drafting of the bill ordering the DNI report. "The Defense Department and Intelligence Community have a lot of work to do before we can actually understand whether these aerial threats present a serious national security concern."
Sen. Mark Warner, the ranking Democrat on the committee, labeled the report "inconclusive" though he said it also "marks the beginning of efforts to understand and illuminate what is causing these risks to aviation in many areas around the country and the world."