In late 2017, scientists at a Hawaiian observatory glimpsed a strange object soaring through our inner solar system. Astrophysicist Avi Loeb conclusively showed it was not an asteroid; it was moving too fast along a strange orbit and leaving no trail of gas or debris in its wake. There was only one conceivable explanation: the object was a piece of advanced technology created by a distant alien civilization.
Professor Avi Loeb wrote about his encounter with this object, ‘Oumuamua, in his 2021 book Extraterrestrial. In this interview, I speak to Avi Loeb about how we would detect the existence of intelligent civilisations beyond Earth, the implications of such discoveries for science, culture, and our planet and why space archaeology could be our species’ most important project.
Q: Why does science shy away from certain topics?
[Avi Loeb]: Science is a learning experience. We are interacting with nature, collecting evidence, and sometimes nature is more imaginative than we are. We ought to be humble when collective evidence, and not assume we know the answer in advance. The answer we think-up, sitting in our office, often doesn’t match the reality. Many of the realities we create are designed to flatter our ego… for example, if we were the centre of the universe, it would have been great! ….but we’re not. If the Earth’s sun was unique and privileged, we’d feel great! ….but it’s not. If we think we’re the smartest kid on the cosmic block when, in fact, there are no other kids out there… it flatters our ego. We prefer to attach ourselves to virtual realities that flatter us, and that’s driven by ego.
When you go into academia, and become an expert, you’ve spent decades practicing a particular niche of research and expect to be able to explain everything based on your past knowledge. That’s a natural tendency. You attach your reputation, success, and ability in that ability to pretend that you know everything. That’s not scientific process.
The only way for you to discover something new is to acknowledge the ocean of ignorance in which you are just an island. Experts have a problem with that – they want to get prizes, and get recognised by their colleagues and peers as being very smart. So, when something new comes along… an anomaly… it often gets dismissed for the sake of reputation management.
If you see an object in the sky… experts who worked on finding and explaining rocks would say this is a rock. What if the rock shows anomalies? maybe it doesn’t look like a rock or comet? The first interstellar object, Oumuamua, was classified as a comet yet, it didn’t show a cometary tail. There was no evaporation from it. Even my most open-minded colleague finds it hard to suggest that it may not be a comet. It’s like this… imagine going to a zoo, and assuming all animals are zebras… you then see an animal, it doesn’t have stripes, it doesn’t look or behave like a zebra, how can you still call it a zebra? That is the mentality of people that want to explain everything based on past knowledge. Others talk of Oumuamua as being a rock of a type we’ve never seen before, somewhat like a cave dweller finding a cell phone.
People are also afraid of the unknown. You worry when you go into a dark alley… in science it is the same. People are worried about what it means if we find a relic of technologies that supersede ours, and which may pose a threat. In 2022, US Congress held open and closed hearings on unidentified aerial phenomenon. They openly discussed the fact that there were 11 incidents of objects passing close to military aircraft and facilities. If the public and government are open minded enough to discuss these things, why is academia lagging?
Q: How does science deal with the weight of major discovery?
[Avi Loeb]: There are heavy things out there, but the weight of things doesn’t mean that we should avoid engaging with them. Imagine the psychological shock my daughters had when they went to kindergarten and discovered that there were other kids around, different to them, some smarter! It was a heavy realisation, but it was reality. The role of science is to educate us about our reality – and we shouldn’t be afraid of it. Once we recognise reality, we can adapt to it. If you don’t recognise reality, you act irresponsibly, and your actions won’t match the environment. Learning about the human body allowed us to develop mRNA vaccines; we don’t shy away from researching the human body because it’s too complicated!
Q: What should we be looking for in our search for the evidence of other civilisations?
[Avi Loeb]: In 2019, a couple of years after Oumuamua was discovered, I found a catalogue the government compiled of meteors. I asked my research student to check if any of the meteors listed in the catalogue moved fast enough to be unbound by the sun (thus coming from outside the solar system). We found one from January 2014 which moved at 60 kilometres per second (relative to the solar system). My colleagues who reviewed the paper said we shouldn’t publish because the uncertainties in the data could be classified (as the data were obtained with a missile warning system). It took three years for me to encourage colleagues from the government to speak about it, and there was a letter sent by US Space Command to NASA saying that they could confirm with 99.999% accuracy that this object came from outside the solar system. This object was 200 times smaller than Oumuamua, but of a sort that is much more abundant. There should be a million-or-so of those objects within the orbit of Earth around the Sun at any given time. The Earth is just like a fishing net bumping into them! The government also released the fireball data, the light curve of the explosion that was triggered by the object colliding with the Earth’s lower atmosphere. We found the object was tougher than iron, and we’re now planning an expedition to Papua New Guinea where we will scoop the ocean floor for the fragments. It will be the first time that humanity puts hands on a material that came from an object bigger than a basketball from outside the solar system. The question therefore is whether it was natural or artificial… We can tell if it’s natural, but of course, it could be some alloy that was artificially assembled. If New Horizons collided with Earth, we could tell it was a spacecraft! It’s important to remember that whilst an iPhone 100 may look like magic (but still recognisable as technology) to us, we may simply not be able to understand a technology which is a million years more advanced than we are. So, we must therefore start by excluding the obvious- is the object natural, if not, was it made by humans…. You exclude the known, and it leaves you only with the unknown!
Our experience is very limited to the surface of this rock we call home. Last summer, you had three multibillionaires who funded trips to ‘space’ they hovered about 70kilometres above the earth’s surface, around 1% of the earth’s radius. The observable universe is 10^19 the size of the earth’s radius. So… showing off by going 1% of the radius of the earth, into space, is a bit of an oxymoron. You cannot show-off in space, we must be humble. The only purpose for us to seek journeys into space is to learn about the unknown. That’s a spiritual conquest. Leaving the solar system has no commercial benefits. You can’t make a business out of leaving the solar system.
Q: Do we have an obligation to leave our solar system?
[Avi Loeb]: When I visit University Hall at Harvard, I find the paintings and statues of the past deans and presidents very disappointing. They’re just physical appearances, right? They’re boring. Within a billion years, the Sun will burn up the surface of the Earth and nothing will remain of those statues and paintings. If you truly want to preserve some notion of yourself, a much better monument would be to send an artificial intelligence to space, an avatar of yourself that carries your flame of consciousness but is also autonomous. Something like that could outlast the Sun and could get to places and reproduce things we care about.
I don’t (frankly) care what people will think of me after I die, but there are things that I care about, and one of them is maintaining the longevity of the things I find precious here. I feel bad looking around and thinking about the fact everything on Earth will eventually disappear. If we think on this, it is quite possible that someone else had this same thought about their civilisation billions of years ago- and they sent things which are flying through space now. Perhaps we’ve just never looked through our window. It’s only in the last decade that we’ve developed the Pan-STARRS survey telescope that can detect objects the size of a football field within the orbit of the Earth around the Sun. Bear in mind, NASA has never launched a spacecraft as big as a football field, and the first interstellar object we detected was only half a metre in size. We are still in the infancy of looking for physical objects, and we’ve spent a long time searching for radio-signals and messages from other civilisations. That’s the wrong approach – we’ve been trying to listen to phone conversations where the sender may not be alive. The approach we need to take is extra-terrestrial archaeology.
I worry that we haven’t checked our interstellar mailbox, and so we’ve missed the letter which contained the recipe for our salvation. Oumuamua was most likely flat (based on the reflection of sunlight), and was very thin. If this was a leaflet sent by another civilisation, we’ve failed to read it. That’s tragic. Perhaps another civilisation sent us a message with the key to our own survival. Physical objects have a huge advantage over listening for signals – you can encode a lot more into a physical object, and observe it for much longer than a pulse of light.
Q: Why do so many of our historic civilisations on Earth speak of interactions with beings from space?
[Avi Loeb]: As kids, we have our parents who look out for us, and look over our shoulders to make sure we are protected. When we become adults, we miss that notion of someone looking over our shoulder. That gives us the concept of God, or perhaps the concept of other beings interacting with us, who are more powerful than us.
Very advanced civilisations may be a good approximation to Gods. We are very close to developing synthetic life in our own laboratories and in the future, if we understand how to unify quantum mechanics and gravity, we may be able to produce a baby universe in a laboratory. These are qualities unto God.
Documented human history is only 10,000 years old. That’s less than one millionth of the age of the universe. It’s quite possible that other civilisations may have visited us before we (humans) existed.
We need to be more open minded. In 1933, Fritz Zwicky inferred the existence of dark matter. We have, since then, invested half a century and billions in dollars looking for it, and have so far not found anything. Imagine if we invested the same money and effort looking for interstellar objects and other civilisations. Why is it that one issue is mainstream science, and another is a taboo?
Q: What would be the consequences to our civilisation, of finding evidence of others?
[Avi Loeb]: My wish would be that if we discover another civilisation, it will teach us that the differences between us humans are insignificant, and that we should treat each other with respect, as equal members of the same species. If we look at human history, the biggest sin of humans is to treat each other as inferior, and the greatest crimes of humanity have occurred because one group of people tried to feel superior relative to another. When you’re not the smartest kid on the block any more, you maybe don’t feel so significant.
In terms of what we could encounter, there are two types of object we could find. One is space-trash. Think about New Horizons or Voyager a billion years from now. They will be non-functioning space trash that will reveal we were here, but nothing more. We could also encounter functioning devices – AI astronauts or functioning, autonomous, devices that other civilisations sent to us. What do we do if we find one of those in our backyard? In truth, we don’t know. We don’t have a protocol – and engaging with such an object could pose a fundamental risk to humanity. It’s a serious policy matter. The only protocol that was discussed in the past relates to what would happen if we get a radio signal or laser burst from a distant civilisation. In this case, we would have plenty of time to respond, but with a functioning object, it’s a whole different ballgame.