In November 2017, an object passed by our planet that was unlike anything astronomers had ever seen. Spotted by a telescope in Hawaii, this strange thing was dubbed ‘Oumuamua. It moved too fast for it to have come from our solar system, its orbit was unusual, and it didn’t have any of the traditional markings of an asteroid or comet. All this led Dr. Avi Loeb to hypothesize that ‘Oumuamua was artificially made, perhaps a piece of technology or some debris from a faraway alien civilization. Before you discount Loeb, you should know that he isn’t the average UFO-spotting kook you might see on a rerun of Unsolved Mysteries. He’s an astrophysicist who has been teaching astronomy at Harvard since 1993, and chaired its astronomy department for nine years. In his new book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, which comes out on January 26, Loeb makes a persuasive scientific argument about ‘Oumuamua’s otherworldly origins, and delves into why his peers have been so hostile to the idea of life outside of Earth.
“Overall, about a quarter of our galaxy’s 200 billion stars are orbited by planets that are habitable the way Earth is, with surface conditions that allow liquid water and the chemistry of life as we know it,” he writes. “Given so many worlds … with similar life-friendly conditions, it’s very likely that intelligent organisms have evolved elsewhere.” The opposition to even the mere concept of extraterrestrial life, Loeb contends, “boils down to conservatism, which many scientists adopt in order to minimize the number of mistakes they make during their careers.”
Intelligencer chatted with Loeb about his theories on ‘Oumuamua, other recent claims from high-profile figures about the existence of aliens, and how the scientific community is responding to his bold claims.
What do you think passed by the earth in November 2017?
The object was discovered by the Pan-STARRS [Panoramic Survey Telescope and Rapid Response System] telescope in Hawaii and was given the name ‘Oumuamua, which means a scout or a messenger from far away in the Hawaiian language. It was the very first object spotted near the earth that came from outside our solar system. It moved too fast to be bound to the sun. It was clearly coming from interstellar space. When this object was analyzed, it looked like there was an extra push on it, in addition to the force of gravity from the sun. Usually with comets, you get this extra push from the cometary tail, the rocket effect. When gases evaporate, and go in one direction, they push the object in the opposite direction, just like a jet plane. The only problem is this extra push was not accompanied by a cometary tail. So what gave it this push remains a mystery.
In September 2020, there was another object that exhibited an extra push without the cometary tail. It was found that the object is actually a rocket booster from a launch of a lunar lander in 1966. Here is an object that we can identify as artificially made, that we produced it, and it behaves in a similar way to ‘Oumuamua.
‘Oumuamua was tumbling and spinning, and the brightness varied by a factor of ten as it was tumbling every eight hours. That means that it has an extreme geometry that is at least ten times longer than it is wide, because as it’s spinning around, you’re seeing the area that reflects sunlight changing by a factor of ten. The best fit for the light curve we saw was a flat object, pancake-like.
These are the facts: A pancake-like object the size of a football field seems to be pushed by a force that is not related to a cometary tail. So we suggested that it’s a light sail, like the sail on a boat that is being pushed by wind. It is a very thin surface that is pushed by reflecting sunlight. We are actually developing light-sail technology for space exploration because it offers the advantage of not needing to carry fuel with the spacecraft. It’s just being pushed by light.
So it seems that ‘Oumuamua is shaped like a disc, which is the stereotypical shape that we associate with UFOs. Is that a coincidence?
It could be a coincidence. It could be just the surface layer of a spaceship or something else that was torn apart. It could be something like a sort of space junk. It’s just like walking on the beach. Most of the time you see rocks or seashells, but every now and then you see a plastic bottle that is artificially made. This could be junk like that. Even if it’s not functional, the significance of ‘Oumuamua is that it implies, perhaps, that we are not alone, that it was not naturally produced, that it was produced by a technological civilization.
It’s a very different type of evidence than in the past. We searched for radio signals. This is very different. It’s like a message in a bottle, a physical object that we trace that is artificially produced. The moral of the story is that even though we didn’t get enough evidence on this object to get an image of it, or be sure that it’s artificial, it is sufficiently intriguing. We should continue to search the sky for similar objects.
Why do you think mainstream scientists generally have a negative response to the notion of extraterrestrial life?
There are several reasons. One is that there is this literature on science fiction and there are also these reports on unidentified flying objects, UFOs, that are not substantiated. The way I approach it is, imagine that there was a lot of literature that is completely fictitious about COVID-19, that makes no sense scientifically and so forth. Would that mean that scientists shouldn’t develop a vaccine? Obviously not. If science can address an issue that was previously in the realm of speculation and didn’t make much sense, that doesn’t mean anything. If the scientists have the instruments to solve the problem, they should approach it without prejudice, without paying attention to the nonsense that was said about it.
I make the analogy, with the human body, that was considered sacred in the Middle Ages. People were not allowed to dissect. Imagine if scientists would say, Okay, because all kinds of nonsense was said about the human body, we would never study it. That would make no sense. We wouldn’t have the health benefits we have now. So the fact that we have this literature that is not scientific [about extraterrestrial life] should not prevent us from working on it, especially now that we have the ability, using telescopes and instruments, to answer this question of whether there are technological signatures out there.
Moreover, it’s the obligation of scientists to do that because the public is extremely interested, and not just poo-poo or have a taboo on any discussion of these matters. I’m trying to change that with my book by discussing it with the media. I appeared on Joe Rogan’s show. I’m getting a very good response from the general public.
Do you think that popular culture has made us unprepared to even consider the idea of alien life?
It’s possible, but scientists should not pay attention to that. In fact, they should have the opposite attitude, and because the public is interested, they should approach it with scientific tools. In the context of objects like ‘Oumuamua, we should find more of the same and see if they are artificial. If there are reports of unidentified objects, we should use the best instruments we have to study them, rather than rely on evidence reported by pilots, who are not scientists.
The problem right now with the kind of subjects that we are talking about is there is not much funding, almost nothing, and young people are discouraged from studying [the possibility of extraterrestrial life] because there is a taboo on those discussions.
Last month Haim Eshed, the former director of space programs at Israel’s Ministry of Defense, told an Israeli newspaper that humans have actually made contact with aliens and have formed a “galactic federation.” What do you make of his claims?
I think it’s irresponsible of reporters to bring up the story without asking him for evidence. Anyone can say whatever they want. There are people who claim that they are Napoleon. And you see that they are not Napoleon. Anyone can say anything and if you report about it, you get a lot of noise that has no meaning.
Reporters never asked Haim Eshed for a document that substantiates what he said. We should not pay attention to someone that says something without evidence. It’s just a pity, because if you listen to too many people saying things that are not substantiated, then it’s hard for the public to select the truth from the noise.
This interview has been edited and condensed for clarity.