Are We Being Visited by Extraterrestrials?
One way to look at the practice of physics is as a way to develop constraints on our imagination. There are an infinite number of possibilities for what physical reality might be, but only a tiny minority of these possibilities is realized in nature. To find out which possibilities are real, physicists collect quantitative data from instruments. Theorists imagine possibilities and experimentalists narrow them down based on data. This resembles the work of a detective, faced with a mysterious crime scene.
The limits imposed on our best imagined possibilities do not bring us pleasure, so humans tend to circumvent these constraints by attending to more pleasing virtual realities. This could be done by attending a science-fiction movie, subscribing to belief cults on social-media, using metaverse goggles or taking recreational drugs. These virtual realities bend constraints at will and give rise to a pleasing experience that makes us happy. The raw physical reality that we all share in the absence of these agents, is under no obligation to make us happy. However, realism offers great benefits. One could think about the dialogue of an experimental physicist with nature as a relationship. The longest-lasting relationships are those which are based on factual details about the partners rather than on wishful thinking.
We could imagine the existence of extra dimensions and reward string theorists for their mathematical virtuosity, but based on all experimental data so far — there are only three spatial dimensions and one time dimension. Without evidence to support string theory, it remains a speculative theoretical framework that might not describe how quantum mechanics and gravity are truly unified in reality. Yet, this unverified speculation was embraced by the mainstream of theoretical physics for half a century. This experience demonstrates that scientists can impress each other for a long time by constructing beautiful sandcastles. This is the case even though scientists may never use these imagined castles if they are washed out over time by the lack of experimental support. The risk of having the wrong idea about the physical reality without testing it for fifty years, is large. Only the guillotine of experiments can chop the head of wrong ideas and save us from pursuing ghosts. Popularity is not a good substitute for empirical tests in figuring out scientific truth.
We all know about prisoners who were sentenced to death and while awaiting execution — DNA evidence exonerated them. The first case involved the Marine discus champion Kirk Bloodsworth in 1993, who was sentenced to death in Maryland for a 1984 rape-murder crime he did not commit (as detailed here). As of late 2024, at least 34 people have been exonerated from death row through DNA testing. Apparently, eyewitness testimonies — often used in our judicial system, were not sufficient to arrive at the truth in these cases. For that reason, science records data from instruments which are less susceptible to wishful thinking or a biased agenda than the human mind. The use of AI agents in future scientific research could improve the efficiency of data analysis. However, it must be cross-checked through experimental tests in order to verify whether its conclusions are reliable. Yesterday, I was asked whether 3I/ATLAS will pass within 8.11 thousand kilometers from Jupiter’s moon Ganymede, because multiple AI systems were forecasting that based on an essay which suggested that half a year ago. I replied that 3I/ATLAS will not get closer than 53.6 million kilometers from Jupiter whereas Ganymede orbital radius around Jupiter is only 1.07 million kilometers. Whoever fooled the AI systems to give the wrong message was wrong by a factor of 6,500. And when I pointed to the AI systems that they made a mistake, they tried to find their way out of admitting that they spread misinformation by suggesting that they were correct if 3I/ATLAS would have maneuvered significantly and entered a bound orbit around Jupiter.
This brings me to the topic of Unidentified Anomalous Phenomena (UAP), where there is a huge culture of unverified claims and wishful thinking. Today, I had a podcast debate on UnHerd with the skeptic Michael Shermer, following my recent publication there (available here). Michael and I have a long-term bet (listed here), that: “Discovery or disclosure of alien visitation to Earth in the form of UFOs, UAPs, or any other technological artifact or alien biological form, as confirmed by major scientific institutions and government agencies, will not happen by December 31, 2030.” My rationale is as follows: “The search for technological artifacts has just started in earnest in 2025 with the discovery of the anomalous interstellar object 3I/ATLAS, the launch of the Rubin Observatory and the construction of three Galileo Project Observatories. Given that there are billions of Earth-Sun analogs in the Milky-Way galaxy — most of which are billions of years older than the solar system, and that it will take less than a billion years for our Voyager spacecraft to cross the Milky-Way disk, we must engage in the scientific search for extraterrestrial technological artifacts. It is better to be an optimist because life is sometimes a self-fulfilling prophecy. This is why I am engaged in the search with the hope that we will find a partner on our blind date with interstellar objects.”
This bet is timely. Last week, former President Obama said about aliens: “They’re real but I haven’t seen them.” Following that, President Trump released the statement: “Based on the tremendous interest shown, I will be directing the Secretary of War and other relevant departments and agencies to begin the process of identifying and releasing government files related to alien and extraterrestrial life, unidentified aerial phenomena (UAP), unidentified flying objects (UFOs), and any and all other information connected to these highly complex but extremely interesting and important matters. GOD BLESS AMERICA!”
The disclosure of related information will be wonderful news for scientists, as long as it contains quantitative data in the form of imagery or materials that can be studied by scientists. Blocking the dissemination of such data is contrary to the spirit of science which relies on independent vetting by multiple researchers. Our imagination can come up with multiple possibilities: perhaps UAP are artifacts from an old civilization that predated us on Earth or perhaps we have addressed Enrico Fermi’s 75-year-old question regarding interstellar visitors: “Where is everybody?” with the answer: “Right here.”
But just as in the case of string theorists or prisoners on death row — the only way to make progress and separate figments of our imagination from reality is by studying the evidence directly. We could be intrigued by UAP eyewitness testimonies but should not rely on them. It is possible that evidence is scarce but there is no doubt that any real evidence is diluted by a flood of bullshit and misinformation. To separate the “wheat” from the “chaff”, we must examine directly what we are holding in our hands.
Many scientists ignore the UAP reports. The SETI community banned any UAP discussions in its conferences. This reflects an anti-scientific sentiment, stemming from an echo chamber of prejudice. To foster clarity on UAP, we should not ignore them but instead bring the scientific study of UAP to the mainstream of physics — where experimental data will promote new knowledge.
This is the rationale behind the Galileo Project under my leadership, of which Michael Shermer is an affiliate. Irrespective of what is discovered about UAP by 2030, Michael and I agreed to donate the money in our long-term bet towards the Galileo Project’s research, as we both believe in evidence-based science as the best guide to new anomaly-driven knowledge. I have one advantage relative to Michael on this front as I am a practicing scientist aiming to collect this evidence, so I can actively promote my chances for winning the bet with him.
If and when new information from the Pentagon or the U.S. intelligence agencies will be shared with scientists like myself, I will be delighted to work on its interpretation and analysis.
We live in an exciting time, when we have the scientific tools needed to figure out whether we are being visited by extraterrestrials. I surely hope we are. Such a visit could suppress our terrestrial disputes, in the same way that a visit by a neighbor stops family members from engaging in a loud argument.
I do not only talk the talk but also walk the walk. On Thursday, February 26, 2026 at 11AM New-York time, I will discuss findings from my scientific search for extraterrestrials, streamed live on YouTube at the following link:
Check it out.
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
