Oumuamua was a mysterious and fleeting visitor. No one was able to observe it in detail, but it was clear that this celestial object was something that had not been seen in space until then.
In October 2017, the University of Hawaii’s Pan STARRS telescope detected this celestial body for the first time — and then several observatories were able to track it for ten nights.
Due to its trajectory and characteristics, astronomers concluded that it could be the first celestial body that passed close to the Earth from outside the Solar System.
For this reason, he was named Oumuamua, a word that in the Hawaiian language means “the messenger who comes from afar and arrives first”.
It was not possible to obtain images or data about its formation, but the existing calculations allow us to estimate that the object was flat, with dimensions of 400 m by 40 m². It had a reddish surface, with an abruptly changing brightness, as well as navigating a chaotic trajectory through the cosmos.
Some astronomers said it could be an asteroid or a comet. A year after the find, however, astronomer and professor of theoretical physics at Harvard University Avi Loeb published a study advocating a much bolder idea.
In it, Loeb points out that the object did not have the tail of a comet and that the data suggest it was unusually bright — at least ten times brighter than the solar system’s asteroids.
Based on this and other “anomalies”, he came to the conclusion that the Oumuamua could be a probe sent by an alien civilization, or the remains of an artifact created by extraterrestrials.
The study generated considerable controversy and criticism from several well-known scientists.
Far from giving in, Loeb stood firm in defense of his thesis and now, in 2021, he has published a book explaining it to the general public, entitled “Extraterrestrial: The first sign of intelligent life outside the Earth”.
In an interview with BBC News Mundo, the BBC’s Spanish service, Loeb comments on his interest in the possibility of extraterrestrial life, explains why he believes it is important to seek intelligence elsewhere in the cosmos and how he defends his ideas about the mysterious Oumuamua.
BBC – You say that seeking extraterrestrial life is the most fundamental question in science. Why?
Avi Loeb – Because finding extraterrestrial life would have a big implication for humanity. It would change our perspective on our place in the universe, our aspirations about space, the relationships between us, international relationships, because we would realize that we are part of the human species and that there is someone else out there.
The best analogy I can make is with my daughters. On their first day in kindergarten, they had a psychological shock, because before, they thought they were the smartest in the world and that the world revolved around them.
When they met other children and realized that wasn’t quite the case, it was a big revelation.
For our civilization to mature, we need to find others.
Furthermore, I look for intelligence in space because I often don’t find it here on Earth. Throughout human history, I’ve seen people fighting each other, trying to feel superior, and that makes so little sense in the grand scheme of the universe, because we’re all so insignificant that there’s no point in trying to be superior to each other.
We could behave much smarter before we were admitted to the intelligence club, so I hope the possibility of extraterrestrial life will convince us to act together and have a better future than our past.
BBC – For you, what is intelligence?
Loeb – For me, an intelligent civilization is one that follows the principles of science, that is, cooperation and the exchange of knowledge based on evidence.
BBC – You say that humans are not special, that we are insignificant, but what is certain is that we are quite complex, no?
Loeb – Yes, but I mean how we feel about ourselves.
In fact, although on Earth we are very special and unique, if you look around you, you will see that approximately half of the Sun-like stars have an Earth-sized planet at approximately the same distance.
This means that not only are we not at the center of the universe, as the philosopher Aristotle has argued and people have believed for a thousand years because it inflated their ego, as, furthermore, we know that the Earth-Sun system is not special; we are not privileged, it is a very common system.
To me this means that the universe is telling us that we should be modest, that we are not particularly privileged. We have similar circumstances on tens of billions of Earths in the Milky Way, and 10 to the power of 21 in the entire universe. That’s more than the number of grains of sand on every beach on Earth.
The number is so large that I wonder how we dare to consider ourselves unique and special.
Furthermore, most stars formed billions of years before the Sun. So it’s very likely that there were things similar to us that existed before us, and if we saw what they did, we could glimpse our future.
BBC – Is that why you say that it is more likely that there are intelligences that are more advanced than we are, rather than less advanced?
Loeb – Yes, one of the reasons is that we’ve only been technological for about a century, and it’s very likely that many of them have been (technological) much longer.
But beyond that, it’s because I have a sense of modesty. When I open cookbooks, I see that with the same ingredients we can make very different cakes.
So what is the probability that, from the mix of chemicals that existed on the early Earth, we got the best cake ever? They are very few.
BBC – What is your idea about the existence of a god and how does it relate to the possibility of extraterrestrial life?
Loeb – We see that our technologies are advancing exponentially, so the technologies that we would develop within a thousand or a million years would not be recognizable today — they would look like magic or a miracle. In the distant future, if we can come up with a theory of quantum relativity that unifies the theory of quantum mechanics and Einstein’s theory of gravity, maybe we can design an experiment that creates a baby universe in the laboratory.
I think sufficiently advanced science and technology can seem to us to be something like a God.
There are already laboratories that are approaching the development of synthetic life, that is, you start with a soup of chemicals and from there you get a living, functioning cell — and I think that in a few decades we will be able to achieve that.
In the past, we believed that a God creates life, but it looks like scientists will be able to do that in this century. And then, in the distant future, if we can come up with a theory of quantum relativity that unifies the theory of quantum mechanics and Einstein’s theory of gravity, maybe we can design an experiment that creates a baby universe in the laboratory.
But if you ask about the religious God that people believe in and that has nothing to do with technology, in that sense I align myself with the notion of the philosopher Spinoza, who basically identifies him with nature.
To me, nature looks incredibly beautiful, and often when I study the universe, I see that it is controlled by the same laws of physics everywhere. The laws we discover in the laboratory apply to the entire universe. It is extraordinary that it is so well organized and so beautiful.
For me, as a scientist, this idea works very well.
But as for this religious God who monitors your actions, out of simple modesty I find it hard to believe. I just don’t think we’re important enough for a God to be monitoring us.
Also, if there are intelligent creatures on other planets, it’s a lot of work to monitor tens of billions of planets and ensure that everything happens as they please.
It seems exhausting to me, and I think God would be above that.
If some alien civilization monitors us, that’s another thing. Then I would say yes, maybe they might be interested in us when they see that we are developing technology.
BBC – What do you think of the methods currently used to search for extraterrestrial life?
Loeb – I don’t think we’re looking for it correctly.
For the past 70 years, this search has been mainly for radio signals. The problem with this is that it’s similar to a phone conversation — you need the caller to be alive, and most civilizations that have existed in the past may already be dead.
That doesn’t mean we can’t search for the tracks they left behind, as we do here on Earth with archeology.
There may be a space archeology, searching for relics or equipment from other civilizations, as if they were bottles thrown into the sea.
BBC – According to your study, one of these alien objects could be Oumuamua…
Loeb – Oumuamua was the first object detected from outside the Solar System, and in fact it looked very strange. It had several anomalies that convinced me it could be an artifact of a technological civilization.
In 2020, the same telescope that detected it observed another object, known as 2020 SO, which behaved similarly, and was the propeller of a rocket built in 1996.
We know then that we humans built that artificial object. The question is who produced Oumuamua. And the way to answer that question is that if another object approaches us, we could detect it early, whether with the Pan STARSS telescope, the Vera C Rubin Observatory (which will be completed in two years in Chile), for example , and we can launch a spaceship equipped with a camera that tells us whether it’s an artificial object or a rock.
If it looks like an artifact, maybe we can land on it, just like the Osiris-Rex mission on the asteroid Bennu did. And we could see which planet it was made on or even try to bring it to Earth, even though it costs a lot of money.
BBC – Is Oumuamua an object built by extraterrestrials?
We don’t know for sure because we haven’t gathered enough evidence.
The reason I say it might be artificial is because of its anomalies. One is that when it rotated, the amount of sunlight it reflected changed by a factor of 10, which means it has a very extreme shape, probably like a pancake.
It also had excessive momentum moving away from the Sun, no comet-like tail, no evaporation of gas or dust that could give it that momentum—so the only explanation I could think of was that it was due to the reflection of sunlight.
For this to happen, the object would have to be very thin, like a sail on a boat, but not necessarily designed to be a sail. Maybe Oumuamua was just a receiver that communicated with probes that are already on Earth.
BBC – Do you rule out the possibility that Oumuamua is the result of a natural process that we humans are still unaware of?
Loeb – After I published my study, other scientists proposed other possible explanations to argue that Oumuamua had a natural origin, but all of them were associated with an object that we had never seen before.
One argued that it was a cloud of dust particles a hundred times denser than air. The problem with that is that as it got closer to the sun, it would heat up and not maintain its integrity.
It was also suggested that it was a football field-sized hydrogen iceberg, which, when it evaporates, does not leave a comet tail because hydrogen is transparent. But hydrogen evaporates too quickly, so it wouldn’t withstand space travel.
Or it was said that it was the fragment of a larger object that destroyed itself. The difficulty here is that, in this case, the result would usually be enlarged parts, not flat ones. (Loeb maintains that Oumuamua would be shaped like a pancake, not a cigar).
My point is that if it’s something we’ve never seen before, we should also contemplate the possibility that it has an artificial origin.
BBC – Are we alone in the universe?
Loeb – Out of sheer modesty, I don’t think so. Also, we didn’t look hard enough to reach a conclusion.
I think not only are we not alone, we may not be the smartest gang on the block.