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Alison Stewart: This is All Of It from WNYC. I'm Alison Stewart, and we'll turn now to the scientific inquiry around the question, are we alone in the universe? How can we, mere humans, go about answering that in a verifiable, quantifiable, scientific way? My guest for this conversation is Avi Loeb, a theoretical astrophysicist and Harvard University professor. He makes the case in his new book that we should be on the lookout for Interstellar space objects, stuff not gravitationally bound any star, and perhaps, the scientists should be using fresh eyes.

In 2017, a cigar-shaped rock spotted by a Hawaiian observatory was the first ever object identified as interstellar. Since then, Professor Loeb has been looking for other possible objects, including one that splashed into the Pacific in 2014. This past summer, he led an expedition to recover fragments. Today we'll be talking about that real scientific work being done in this area. We will not be talking about the controversial UFO enthusiasts who presented a set of humanoid-looking bodies to Mexico's congress last week.

That was widely panned as a hoax, but we will touch on the US Congress's hearings into apparent unidentified aerial phenomenon that US military service members claim to have been seen behaving in a way that seemed to defy the laws of physics. Here's how former Navy Pilot Ryan Graves described one sighting.

Ryan Graves: Some of the behaviors that we saw in a working area. We would see these objects being at 0.0 mock, that's zero air speed over certain pieces of the ground. What that means, just like a river, if you throw a bottle in, it's going to float downstream. These objects were staying completely stationary in category-four hurricane winds. These same objects would then accelerate to supersonic speeds, 1.1, 1.2 mock and they would do so in very erratic and quick behaviors that I don't have an explanation for.

Alison Stewart: That doesn't necessarily follow that they must have been seeing technology from another world, and that's because there's believing, there's seeing, and then there's scientifically proving a standard that bears a much higher burden of methodological rigor, free from biases and stigma and all that other human psychology. Which brings us back to Professor Avi Loeb here to talk about his new book, Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars. Professor, welcome to the show.

Avi Loeb: Thanks for having me. It's a great pleasure.

Alison Stewart: From your perspective, what is the purpose of investing and exploring interstellar engagement?

Avi Loeb: We know that over the past half a century we launched five probes to Interstellar space that was Voyager 1, Voyager 2, Pioneer 10, Pioneer 11, and New Horizons. We just had a one century of science and technology. Imagine those other stars that formed billions of years before the sun. Most of them actually, having a planet like the Earth next to them, we know that at least a few percent of them have. Those civilizations preceded us by enough time to actually reach our doorstep with chemical propulsion, the type that we used.

The question is how much space trash do we have near us? It's not a philosophical question. We can use telescopes to search for interstellar objects, and only over the past decade we discovered the first ones. What intrigued me is that the first two of them looked unlike the rocks that we are familiar with, the asteroids or comets that we know about. The first one was actually in January, 2014, almost a decade ago. It was an object that collided with Earth roughly half a meter in size spotted by US government satellites.

What was unusual about it is that it was moving very fast. It was unbound to the sun, came from outside the solar system based on its high speed. Even outside the solar system, it was faster than 95% of all the stars in the vicinity of the sun. Moreover, it maintained its integrity despite the immense, stress that it had on its surface. We calculated that it was tougher than all space rocks from the solar system, 272 of them cataloged by NASA over the past decade.

That raised the possibility that it's just like a voyager meteor. Imagine voyager sometime in the future colliding with another planet like Earth and appearing a semi-meteor of unusual material strength and unusual speed. To check it out, we just did what the scientific method asks for. I led an expedition to the Pacific Ocean, the location of this meteor, to collect materials that were left over from it. We found those materials, and I can elaborate more.

We also analyzed the materials and figured out that the composition is not from the solar system. It must be material from outside. It could be a natural origin. We talk about it in the scientific paper that we submitted for publication, but it also is possible that it's technological in origin.

Alison Stewart: I want to go back to something you said because I think it's fascinating. How is the speed determined that speed that lets you know it came from, it's an interstellar object?

Avi Loeb: When an object collides with Earth, it actually goes through the atmosphere, the air and then when it gets to the lower atmosphere, it burns up. Most of the meteors burn up at an elevation of 40 to 70 kilometers, very high in the atmosphere. This one disintegrated about 20 kilometers above the Pacific Ocean. It went deeper into the atmosphere where it was encountering stress, far greater than all other meteors that we see.

What you see is the fireball that is created as a result of the heat deposited by the friction of the object with air. As the fireball moves across the sky then that allows you to measure its velocity. That's what the US government satellites recorded as well as some ground-based sensors. You can basically see the ball of fire created by the object as it burns up moving.

Alison Stewart: My guest is Professor Avi Loeb. The name of the book is Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars. Professor, what do we stand to learn from interstellar objects that we can't learn from others?

Avi Loeb: It's an opportunity to study objects that came from other environments. Just think about going to your backyard where you see the familiar rocks, that you saw over and over again. Every now and then, you might notice an object that came from the street. This object could first of all tell you something about what happens in the street, but it also holds the potential of being thrown by a neighbor if it's a tennis ball, for example. It's just a way, a completely new way that was not explored before the past decade of learning about what lies outside the solar system.

Of course, the experts on space rocks within the solar system argue again and again that anything we see in the sky must be rocks, must be stones of the type that we had seen before. Obviously, most of them are because they come from our vicinity within the solar system, but this interstellar meteor came from outside and they still want to fit the data for it with a stone to the point that I call it, the stone age of science where everything in the sky, it must be stones.

That's not a good, healthy attitude because the data, for example, on this one from the US space command implied that, this object must have material strength larger than the rocks we find in the solar system. The composition that we found could explain it because it was not just iron that dominated the composition, but we found a very high abundance of heavy elements between lanthanum and uranium. In principle, that can explain the high material strength. We can even test it in the laboratory by taking those ingredients just like you make a cake. You put the ingredients together and you see what a cake you get, so we can see what materials we get.

I should say uranium for example, was almost 1,000 times more abundant than in the solar system standard composition and lanthanum was actually 500 times more so. These were very high abundances. I have an idea of maybe a natural environment that can give rise to that, which we mentioned in the paper and I'm working on right now. Someone also commented to me that semiconductors have substrates that are reaching lanthanum and molybdenum. Maybe it could also be artificial, but the way to figure out whether it's natural or artificial is to find a big piece of the object. You can easily tell whether it's a rock or a gadget. That's what we plan to do in the follow-up expedition that we hope to have within the coming year.

Alison Stewart: I hope this isn't too basic a question, but I'm hoping you can draw a line for our audience. What is it about Interstellar space that draws you to focus as a scientist interested in the search for alien intelligence?

Avi Loeb: Oh, there is much more real estate out there. We know of the intelligence we have here on Earth and we thought that we are the smartest on earth, which was justified until recently. Now, we're developing large language models of artificial intelligence that could outsmart us in the near future. Suddenly, that will be a sober realization that we are not the pinnacle of creation in terms of our intelligence. We are creating technological kids that could be better than us in some ways. We already have some alien intelligence that we are developing. It will not be like biological intelligence. It will be different because it's made of metal. It's very different than biological tissue.

It's actually quite amazing that the human brain is so small and so capable. It may not represent the ultimate level of intelligence. What makes me curious about interstellar space is because the experiment we have here on Earth may have been happening over and over again in many other environments. Perhaps they already represent our future, our technological future. We can learn from that. Also, we can learn how to survive long because it's only those successful civilizations that we will hear about. Those that were engaged in territorial disputes and invested all their money fighting each other and killing each other, the way we behave very often.

Alison Stewart: That was interesting. There's a point in your book when you write about how when the military is put in charge in these kinds of investigations, they're looking at everything in an adversarial light, and that really, science should be leading the way.

Avi Loeb: Obviously, the US government is interested in national security more so than any scientific aspect of what I was describing. I am completely complimentary to that. Anything that says made in China on it is boring as far as I'm concerned because I want to know if anything came from outside of this Earth. I hope that it will inspire us to do better as a civilization rather than engage in military conflicts.

We invest $2 trillion a year in military budgets worldwide. If we were to allocate it to space exploration, we could send a CubeSat, the probe, towards every star in the Milky Way galaxy within one century, billions of them. It's just a question of priorities. My hope is that realizing that we have a neighbor will perhaps inspire us to do better. Then we will realize that it's better for us to work together because we are all equal members of the human species. We are all in the same boat, the earth sailing through space. This will be a wake up call for us.

Alison Stewart: My guest is Professor Avi Loeb. Professor Avi Loeb. The name of the book is Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars. One of our listeners called in with a question. New York Senator Gillibrand has been instrumental in legislation to fund the office that studies UFOs as well as passing legislation that protects whistleblowers. The caller wants to know what you thought of that, and maybe what you think the government should be doing.

Avi Loeb: The fundamental question is whether there is classified data or materials that are in possession of the government, that are not available for us in the public. If so, that should change because anything about interstellar space, outside the solar system, has nothing to do with national security. It should be part of science. The best minds in the world in science should try and figure it out rather than the government keeping it secretive. As Senator Gillibrand advocates for, I very much hope that any such information will eventually be released to scientists.

There is a new office in the Pentagon, all domain anomaly resolution office but again, it focuses on national security concerns. NASA recently responded to a report of a study that they appointed, which again established a collaboration with the Pentagon. In a way, I'm a little bit disappointed. If we wait for government to tell us what lies outside the solar system, we may wait forever. The sky is not classified, the oceans are not classified. We can figure it out ourselves. The only obstacle that I see is the stigma or the ridicule or people having an opinion without seeking evidence.

Alison Stewart: We've seen the private sector's interest in space grow over the past decades. Is there anything about the search for interstellar or extraterrestrial intelligence that would appeal to commercial companies? What do we need to-- gosh, I'm thinking about protections or guardrails that need to be put in place given the private sector's behavior on occasion.

Avi Loeb: Of course if we discover technologies of the future, they would have commercial value if we import them to Earth. If we find a gadget that was manufactured by an advanced technological civilization, it may be something that you can make a profit of. My funding as of now is coming from people who are curious and donors that just want us to figure out if we have a neighbor. With all the implications, they're not really after the commercial benefit.

Of course, if we find something with The Galileo Project that I'm leading, I'm sure there will be lots of commercial interest in that. This is not the primary motivation. It's basically childlike curiosity, trying to figure out what is in our neighborhood. If there is a smarter kid in our neighborhood, we better know about it because we can learn from him.

Alison Stewart: Let's talk about that kid in the neighborhood, the family paradox, which is everything is so vast and there's so many stars in planets. It's very likely that life does exist. Why haven't we seen or encountered them yet if there's so many and so likely?

Avi Loeb: For 70 years, the SETI community, the Search for Extraterrestrial Intelligence Community was looking for radio signals, which is very similar to waiting for a phone call. Nobody may call you when you're listening, especially if it's only over less than a century, because that's a small part. That's one part in a hundred million of the age of the universe. They may not have been transmitting exactly at the time that you're waiting for the signal. Another approach, which is the one that I prefer, is to look for any packages in our backyard or near our mailbox.

That's a completely different approach because the sender may be dead. We don't need the sender to do anything if the package arrived to our neighborhood. When Fermi asked some 70 years ago, "Where is everybody?" That was a very lazy proposition because he did not use telescopes to check where they are. He was just asking, "Why isn't there any evidence next to me in Los Alamos when I'm having lunch about them?"

That is like a single person standing at home and saying, "I don't see any partner around me. Perhaps there is nobody out there that I can live with." We all know that to find a partner, you need to go out to dating sites, you need to look through your windows. You better leave your home and check around. You can't just say, "Where is everybody?" That's inappropriate.

Alison Stewart: Your analogies are excellent. My guest has been Avi Loeb, professor of astrophysics. The name of the book is Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars. Thank you for taking the time today.

Avi Loeb: Thanks for having me.

Alison Stewart: There is more All Of It on the way. Author Hannah Carlson joins us to discuss her latest book, Pockets: An Intimate History of How We Keep Things Close. That's coming up after the news.

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