Have UFOs been shown to be alien spacecraft?

What was actually observed?

The best-studied reports come from U.S. military pilots and sensors. In June 2021, the Office of the Director of National Intelligence (ODNI) published a preliminary assessment of 144 reports from U.S. government sources, covering 2004 to 2021. In 80 of them, more than one sensor picked up the object, such as radar, infrared cameras or a pilot’s own eyes. The report judged that most of these were probably real physical objects, not just glitches.

Some of the reports were striking. In 18 incidents, described in 21 reports, observers said the objects seemed to hover in high winds, move against the wind, turn suddenly or move fast with no visible engine. The task force also had 11 reports of pilots’ near misses with UAP. The report said UAP “clearly pose a safety of flight issue.”

The report was also honest about its limits. The team could identify only one object with high confidence: a large, deflating balloon. The rest stayed unexplained. The team said the odd motions “could be the result of sensor errors, spoofing, or observer misperception” and needed more study. It also noted that military sensors are built for other jobs and are “not generally suited for identifying UAP.”

What did people infer from it?

Some people concluded that the unexplained objects were alien craft. The idea grew stronger in July 2023. At a House hearing on July 26, 2023, David Grusch, a former intelligence officer who had served on the government’s UAP task force, testified under oath. He said he “was informed” of “a multi-decade UAP crash retrieval and reverse engineering program.” Asked whether bodies were found, he said “nonhuman” biological remains were recovered, based on what people on the program told him. Asked whether he had seen any of the bodies, he said, “That is something I have not witnessed myself.”

That testimony should be described fairly. Grusch spoke under oath, and he said he was reporting “the facts as I have been told them.” When lawmakers asked for details, such as whether he had seen crash imagery, he often said he could not discuss it in an open session. So his claims are serious claims made under oath. They are not yet backed by evidence the public can examine.

Does the evidence support the alien inference?

So far, no. Three kinds of reviews point the same way.

Solved cases turn out ordinary. ODNI’s 2022 annual report described a first pass at 366 newer reports. It sorted more than half into ordinary groups: 163 balloon or balloon-like, 26 drones and 6 clutter, such as debris. The Pentagon’s All-domain Anomaly Resolution Office (AARO) has since closed many more. Its 2024 annual report covered 757 reports. Every case it resolved turned out to be something like balloons, birds, drones, satellites or aircraft, and it stated that it had “discovered no evidence of extraterrestrial beings, activity, or technology.” Its next annual report, covering June 2024 to May 2025, resolved 370 cases, all to ordinary causes, from balloons to one rocket launch and one jet pack. A new modeling tool also let it solve 238 reports as sunlight flashing off satellites.

Famous videos can fool the eye. Take the Navy video known as “Go Fast,” recorded off Florida in January 2015. It seemed to show an object racing just above the ocean. AARO’s 2025 analysis worked out that it was really about 13,000 feet up, moving at about 72 to 161 miles per hour, much of it simply the wind carrying it along. It never moved against the wind. The high speed was an illusion called motion parallax. AARO still cannot say what the object was. But it found nothing anomalous about how it moved.

The crash-retrieval claims were checked. AARO’s historical report (Volume I, 2024) reviewed U.S. investigations back to 1945 and interviewed people who described hidden alien programs. It found “no empirical evidence” that the government or companies had been reverse-engineering alien technology. It said many of the programs people named were real, sensitive national security programs that were mistaken for alien ones. A metal sample said to come from a crashed craft proved to be an ordinary Earth-made alloy, mostly magnesium, zinc and bismuth.

NASA’s independent study team, 16 experts led by astrophysicist David Spergel, reported on September 14, 2023. It wrote that there is “no conclusive evidence suggesting an extraterrestrial origin for UAP” in the peer-reviewed literature. It called alien life “the hypothesis of last resort,” the answer to reach for only after other options are ruled out.

What is the strongest objection, and what do people get wrong?

The strongest objection is simple: the government keeps things classified. If it hid something, why trust its own reports? That concern is fair. AARO itself says real, sensitive programs have been mistaken for alien ones, and ODNI noted that pilots faced stigma for reporting sightings. But the answer to secrecy is evidence that anyone can check: sensor data, samples tested by outside labs, documents. So far, no such evidence has been made public. A claim can be sincere and still not be shown.

The most common mistake runs the other way. People treat “unexplained” as “unexplainable,” or as “alien.” It is neither. Most open cases are open because there is not enough data. In AARO’s latest report, 191 of 319 new reports were set aside for exactly that reason. A blurry video is hard to solve because it is blurry, not because it is alien.

Ordinary things can look very strange. The reports list “party balloons” and large research balloons, satellites that flash brightly when sunlight hits them, drones, birds and aircraft. A camera on a moving jet can make a slow object look fast. None of this means every witness was careless. Trained people see real things. The question is what those things were.

What is still unresolved?

Quite a lot. AARO’s latest report flagged nine new reports as meriting further study, and it is still investigating a Navy report of about 100 airborne objects off the coast of Virginia. ODNI’s 2022 report also said some of its 171 uncharacterized reports seemed to show unusual flight characteristics and needed more analysis. Whether life exists anywhere else in the universe is also still open. NASA says it has found no credible evidence of life beyond Earth, and no evidence that UAP are extraterrestrial, while it keeps searching. For the wider question of why we have not found anyone, see our story on the Fermi paradox.

How can you check it yourself?

• Read the reports, not the headlines. The ODNI 2021 assessment is short. AARO posts its annual reports and case write-ups on its website.
• Ask four questions about any video: What sensor took it? How far away was the object? How fast was the camera moving? Is the raw data available?
• Check the sky. Free satellite-tracking apps show when satellites will pass overhead, which helps with bright moving lights.
• Separate claims from evidence. Testimony under oath is a serious act. It still does not turn a secondhand account into proof.

For a closer look at what each report said, see our story What Do Official UFO and UAP Reports Actually Say? and our guide on how to check a viral science claim.