About Aliens and Earthlings
Below is a set of cosmos-wide set of questions (marked in boldface), posed to me today by a reporter in Athens, Greece, along with my answers.
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We are living in an era of wars, climate crisis, political polarization and technological acceleration. As someone who spends his life looking at the cosmos, how do you make sense of this particular moment in human history? What kind of era do you think we are living in?
We are approaching a major revolution in human history. The exponential growth of artificial intelligence (AI) capabilities and the potential discovery of alien intelligence could make our future completely different than our past.
Discovering that we are not the only technological civilization in our cosmic neighborhood resembles hearing a knock on the door by a neighbor. Hopefully, the outside perspective will quiet down the loud arguments among our family members on Earth.
The recognition that we are not alone holds the potential of changing our priorities from conflicts to cooperation among all humans on Earth. We are all in the same boat when dealing with interstellar visitors. At the same time, it is important to make sure that no passenger within our boat acts irresponsibly because such behavior affects all of us.
The Galileo Project is now five years old. What have you learned that you didn’t expect to learn when you started it?
The research team of the Galileo Project had monitored millions of objects in the sky and learned that the vast majority of them are human made or natural phenomena. We are seeking rare outliers to these categories. Even if one object is extraterrestrial, it would be the biggest discovery that humanity ever made. We only need to find one. That particular object could inform us of new science and technology that we do not possess, as well as better our geopolitical priorities on Earth and ambitions in space.
You recently announced that the Project can now measure distances to objects in the sky with better than 10% accuracy, using multiple observatories separated by 10 kilometers. What does this mean in practical terms for your research?
The ability to triangulate objects by observing them from three different directions is a new feature that the Galileo Project employs in Nevada, where we have three observing units separated apart by 10 kilometers. This allows us to infer position, velocity and acceleration of each object in three dimensions. From a single vantage point, a nearby object — like a bug or a bee, may appear to be large or cross the sky fast even though it moves at a relatively low speed. The UFO files released by the Pentagon over the past month do not provide distance information. As a result, it is impossible to conclusively determine whether any of the recorded objects moves outside the performance envelope of human-made technologies, like balloons, drones or airplanes.
After the release of the UFO files in May 2026, your team concluded that none of the objects requires an exotic origin. Were you disappointed by that — or relieved?
I would like to know the nature of all anomalous objects in the sky. In that context, I was disappointed by the lack of sufficient information to make this determination. We are left with uncertainty and need higher quality scientific data.
The good news is that we do not need to wait for the government to tell us what lies in the sky. We can simply look up. This is what the Galileo Project under my leadership is doing by employing state-of-the-art instrumentation and computers.
The government has better quality data, for example from the fleet of satellites that it employs to image the Earth at high spatial resolution of a few centimeters, but such data was declassified as of yet.
Does Oumuamua still occupy your thinking, or have you moved on to other hypotheses?
As a scientist, I am driven by data. The most interesting data carries anomalies which potentially flag new knowledge. Unfortunately, we have acquired limited data on the first recognized interstellar object, 1I/`Oumuamua, which left us in 2017 with uncertainty about its nature. It was most likely a flat object with an extreme shape based on the fact that the amount of sunlight it reflected changed by a factor of 10 as it was tumbling every 8 hours. In addition, it was pushed away from the Sun by a mysterious force, without showing any evidence for cometary outgassing. I proposed that this force was simply a result of the reflection of sunlight, which meant that the object is very thin. Three years later, another object named 2020 SO was discovered by the same telescope in Hawaii. This one was definitely pushed by reflecting sunlight. Within a few months, 2020 SO was identified as an upper stage of a lunar lander mission by NASA — launched in 1966. We know it is technological and made of thin walls because we launched it. The question is who launched 1I/`Oumuamua?
1I/`Oumuamua’s anomalies intrigued me to study in detail subsequent interstellar objects like 3I/ATLAS which was discovered in 2025. Shortly after 3I/ATLAS was reported to move in the orbital plane of the planets around the Sun to within 4.88 degrees, I defined the Loeb Classification Scale which ranks an interstellar object that is definitely of natural origin (namely, a natural rock or iceberg) as 0 and an object that definitely represents alien technology and poses a threat to humanity as 10. I ranked the anomalies of `I/`Oumuamua and 3I/ATLAS as 4 on the Loeb Scale, as they feature anomalies that are intriguing but insufficient to lead to the conclusion that they represent alien technology.
The Pacific expedition retrieved materials from the 2014 interstellar meteor IM1. What exactly did you find, and why do you consider it significant?
We recovered molten droplets, less than a millimeter in size, from the crash site of the interstellar meteor IM1 and found that a tenth of them have a chemical and isotopic composition that deviate from solar system materials and are most likely extrasolar. If true, this is the first time that scientists studied in a laboratory the materials from a large object that arrived from outside the solar system.
If IM1 or Oumuamua were proven to be of artificial origin, what would change for humanity and what wouldn’t?
Discovering alien technology would change our perspective about our place in the Universe and inspire us to invest more in space exploration. We might be tempted to visit the backyard of those who sent probes to our backyard. Religious people would realize that God is not a parent who attends to a single child. The conceptual revolution will take time to affect the mindset of all people on Earth. Some may continue their daily routines and obsession with earthly matters for years after the discovery.
Most of your academic colleagues continue to treat your research with skepticism. Does that hurt you, or does it drive you?
I learned to ignore the audience. Good basketball players keep their eyes on the ball, not the audience.
Is there a line between scientific courage and scientific irresponsibility — and who gets to draw it?
Of course. Scientific progress is driven by paying attention to anomalies in data. It requires childlike curiosity. Scientific irresponsibility is to engage for decades in a belief system that cannot be tested by collecting data on the physical reality that we all share. You might think that I am referring to religious cults, but I am actually referring to the mainstream of the physics community which contemplated in recent decades the untestable concepts of string theory or the multiverse.
You often say that science must follow the data wherever it leads. But data requires interpretation. Where does the scientist’s subjectivity begin?
Subjectivity begins in what the science community regards as worth the effort of data collection. It took four decades between the suggestion made by the astronomer Otto Struve to search for Jupiter-mass planets close to Sun-like stars and the discovery of the hot Jupiter 51-Pegasi b because observers decided not to waste their time in search for such systems. Revolutionary data requires the willingness to collect it. The lack of curiosity by risk-averse gatekeepers is what suppresses innovation in science.
Doing science by consensus is bad for progress, because the beaten path might lead towards a dead end. An example is supersymmetry which was adopted by the mainstream of theoretical physics and not discovered in its natural parameter space by CERN’s Large Hadron Collider.
If extraterrestrial intelligence exists, why do you think it hasn’t communicated with us in an unambiguous way? What is the most compelling explanation you have?
We may not be interesting to them. We tend to think that they care about us for the same reason that we believed that we are at the center of the Universe.
Instead of thinking about ourselves as the focus of cosmic attention, we should seek more accomplished partners. For our blind date with interstellar partners, we should aim high and not low. Instead of searching for the most abundant and mediocre dating partners in the form of primitive lifeforms like microbes, the mainstream of the astronomy community should search for beings who are more intelligent than we are.
The Fermi Paradox remains unanswered. Which version of it do you find most plausible today?
They might be right here. We have not done a proper search in our cosmic backyard.
If it were proven that we are not alone in the universe, would that be good news or bad news for humanity?
It would definitely be good news, akin to finding a more accomplished sibling in our family of intelligent beings. We might be jealous of their accomplishments, but at the same time — they might inspire us to do better.
You studied philosophy before turning to physics. How much has philosophy shaped the way you do science?
I am interested in the most fundamental questions about our existence. As a scientist, I narrow down this set of questions to those that we can answer by collecting data.
You have written that curiosity matters more than certainty. In a world that demands quick answers, how do you teach tolerance for uncertainty?
Uncertainty is the most common condition in practicing science. We have to live with it because our knowledge is an island in an ocean of ignorance. The science influencers who give us a false sense of certainty through papers or social media posts might be guiding us in the wrong direction. In 1894, the physicist Albert A. Michaelson argued that physics is over and what remains is measuring the constants of nature to the fifth decimal point. This was a decade before Special Relativity revolutionized our concept of spacetime, two decades before gravity was interpreted by General Relativity as the curvature of spacetime and three decades before Quantum Mechanics revolutionized the way we view the physical reality.
If you could send a single message to an extraterrestrial intelligence, not a scientific one, but a human one, what would you say?
“Where is the nearest hub of intelligent civilizations?”
Outside the laboratory and beyond the telescopes, what do you love most in life? Not the scientist, not the professor. The person. What truly matters to you?
I love my family and enjoy nature. I jog 5 kilometers every morning before sunrise, in the company of birds, wild turkey, bunnies and ducks. If AI will bring us to a catastrophic singularity, I plan to disconnect from the internet and live in harmony with nature.
On warm summer nights, when you step outside and look up at the stars, what goes through your mind? Not the scientist’s thoughts. The human ones.
The stars of the Milky-Way galaxy which streams through the Local Group look to me like lights from the cabins of a giant spaceship sailing through space. I often wonder whether there are other passengers in these cabins.
You were born in Israel, you served in the Israeli army, and you have spent your career at Harvard looking for common ground between humanity and the cosmos. How do you carry that tension, between a world that keeps dividing itself and a universe that knows no borders?”
I ignore the limitations of the current human activities on Earth and focus on what will be remembered in the history books of the Milky-Way galaxy within billions of years from now.
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.
Professional website:
https://lweb.cfa.harvard.edu/~loeb/
Social media:
https://avi-loeb.medium.com/
https://www.youtube.com/@ProfessorAviLoeb
https://open.spotify.com/show/1zhndXkvSY2b8FdjspFpCd
https://x.com/ProfAviLoeb
