# Extraterrestrial by Avi Loeb - Blinkist What’s in it for me? A bold interpretation of recent discoveries. In late 2017, the world was rocked by a stunning announcement. Scientists at the Haleakalā Observatory in Hawaii had detected an unusual object passing through our solar system – the first discovery of its kind. They named the object ‘Oumuamua. But , what exactly was this strange object? No one knows for sure, but the esteemed Harvard astronomy professor Avi Loeb has a theory: ‘Oumuamua is a piece of extraterrestrial technology. Drawing on Loeb’s years of experience and keen, imaginative scientific eye, these blinks lay out the professor’s controversial argument that ‘Oumuamua could be an artificial probe sent to observe our solar system. Along the way, you’ll learn what makes this object so unusual and what its visit means for our understanding of the universe. In these blinks, you’ll learn what the word ‘Oumuamua means; why theoretical physics gets all the attention; and how we might spread humanity across the galaxy. ‘Oumuamua is unusual for visiting from beyond our solar system. October 19, 2017. The astronomer Robert Weryk is poring through data collected by the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS for short, a network of telescopes that sits atop the mountains of Maui, in Hawaii. As he looks at the day’s observations, he notices something strange. Pan-STARRS has picked up an object jetting away from the Sun at 58,900 miles per hour. At such speeds, the object is set to soon leave our solar system forever. Yet, the object’s trajectory is even more interesting. Judging by its path, it appears that it must have come from outside our solar system! Weryk is stunned. He’s just stumbled upon the first interstellar object ever detected by mankind. The key message here is: ‘Oumuamua is unusual for visiting from beyond our solar system. When Weryk delivered the news of his discovery to the International Astronomical Union, they dubbed the object ‘Oumuamua. This Hawaiian word roughly translates to “a messenger from afar arriving first,” or more simply, “scout. ” It’s a fitting name, as ‘Oumuamua is the first nearby object – astronomically speaking – ever detected that does not have origins within our solar system. So, if ‘Oumuamua isn’t a local, where is it from? Well, we don’t know exactly. What we do know is that it comes from the direction of Vega, a star located about 25 light-years away. We also know that it entered our solar system on a hyperbolic trajectory. This means that it doesn’t orbit the Sun like an asteroid or comet, but instead, it comes from the outer reaches of space, passes by the Sun once, and then escapes off into space again. Prior to detecting ‘Oumuamua, astronomers had observed both objects within our solar system and objects very far away, like distant stars and planets. Yet, they had never seen an item from interstellar space pass through our solar neighborhood. Of course, they knew it was possible. Humans themselves have already launched five objects into interstellar space, including the Voyager, Pioneer, and New Horizons space probes. Since this initial discovery, scientists working at Pan-STARRS have already discovered several more interstellar objects swinging by our Sun. Yet, ‘Oumuamua still stands out – and not simply because it was the first object found. In fact, ‘Oumuamua has many particular qualities and unusual traits that leave scientists puzzled. We’ll look at those in the next blink. ‘Oumuamua doesn’t look or act like any known object. Imagine you’re a detective. For your next assignment, you’re tasked with discovering all you can about a certain mysterious object. But there’s a catch. You can’t examine the object. Not only is there no clear picture to look at, but the item itself has left the solar system forever. This is the challenge facing astronomers studying ‘Oumuamua. When scientists first spotted it, ‘Oumuamua was already speeding away. The scientific community had only 11 days to collect data about the ever-distant enigma. Even so, the collected data raised more questions than answers. The key message here is: ‘Oumuamua doesn’t look or act like any known object. When it was discovered, most scientists assumed ‘Oumuamua was something like a comet or an asteroid, albeit one from outside our solar system. These types of objects are very common throughout the galaxy, and scientists have a strong handle on their appearance and behavior. But, intriguingly, ‘Oumuamua doesn’t precisely align with these known categories. Let’s start with ‘Oumuamua’s shape. Scientists can accurately estimate any object’s dimensions by carefully observing the way light reflects off its surface. In the case of ‘Oumuamua, the Sun’s reflection varied in brightness by tenfold every eight hours. This indicates a long or flat object, perhaps several hundred yards long and only several yards thick. Asteroids or comets are much rounder and don’t come close to these dimensions. Also of note is ‘Oumuamua’s unusual trajectory as it left the solar system. By accounting for gravity and other forces, astrophysicists are quite adept at calculating an object’s flight path. However, as it passed the Sun, ‘Oumuamua deviated from the predictions. Most noticeably, the object sped up as it left as if it were pushed by some additional force. Now, this behavior sometimes occurs in comets. The acceleration is caused by water and other particles evaporating from the comet as it heats up – this is called outgassing and is responsible for a comet’s tail. Yet, no trace of this process was observed from ‘Oumuamua. Even the combined observations of three specialized infrared satellites turned up no evidence of outgassing. So, given these strange deviations, should we try to fit ‘Oumuamua into our previously known classification system? Or, should we be open to exploring more exotic possibilities? There’s a real possibility that ‘Oumuamua is alien technology. It’s 17 months before ‘Oumuamua graced our solar system, and astrophysicist Avi Loeb is hard at work on a goat farm in rural Israel. However, Loeb isn’t tending to the livestock. He’s putting the finishing touches to a bold proposal. It’s called the Starshot Initiative. This plan outlines a realistic way for humanity to send a probe to Alpha Centauri, a star system some four light-years away. The probe would be powered by a lightsail, a theoretical technology that harnesses the power of light just as a ship’s sail captures the wind here on Earth. At the time, no one had seen a lightsail in action. Though, as Loeb learned more about ‘Oumuamua, he began to suspect the mysterious object might be a real-world example. The key message here is: There’s a real possibility that ‘Oumuamua is alien technology. By 2018, the scientific community was in agreement: ‘Oumuamua was indeed a very strange object. The item’s unusual proportions, brilliant luminosity, and unexpected flight path all suggested that it was not any type of previously known space phenomena. Yet, there was no consensus on what ‘Oumuamua actually was. So, Loeb, along with his postdoctoral fellow Shmuel Bialy, made a suggestion: ‘Oumuamua could be a lightsail. Building from observational data, the two demonstrated that the object could have a huge surface area and a minuscule thickness of just a few millimeters – the exact right proportions of a lightsail. Moreover, using a series of well-grounded calculations, they showed that such a shape could explain the object’s unusual acceleration. Loeb and Bialy published their findings in the prestigious scientific outlet Astrophysical Journal Letters. In their paper, they argued that their interpretation of ‘Oumuamua was completely consistent with the evidence presented. They also argued that while science couldn’t rule out a natural explanation for the object’s strange anomalies, it also couldn’t ignore the very real possibility that ‘Oumuamua was a specifically designed piece of artificial technology. The paper caused an uproar. Predictably, the popular media loved the story. Suddenly, every news outlet wanted to talk to Loeb about his alien conjecture. However, the scientific community was not as enthusiastic. Many scoffed at the idea. The International Space Science Institute even published a rebuttal denouncing Loeb’s claims as meritless. But, if there’s even a tiny possibility that ‘Oumuamua is actually artificial, shouldn’t we entertain the idea? We’ll explore that question in the next blink. Scientists are irrationally opposed to the possibility of extraterrestrial life. By now, it’s clear that ‘Oumuamua is an exceptionally strange object. Yet, if we consider ‘Oumuamua’s velocity-position, it becomes even stranger. Every object in the galaxy is moving. An object’s velocity-position is its movement as compared to all other objects. Some velocity-positions are faster, others are slower, and amazingly, ‘Oumuamua’s was nearly exactly average. It occupied something called the local standard of rest, meaning that on a galactic scale, it was essential standing still. What could account for this exceedingly rare quality? Is Oumuamua a buoy meant to mark a path? Is it a node on a galactic communication grid? Or does it serve some other unfathomable alien function? There’s no way to know but thinking through these exotic possibilities is crucial. The key message here is: Scientists are irrationally opposed to the possibility of extraterrestrial life. For most scientists, investigating the possibility of intelligent life beyond our solar system is a frivolous pursuit. Very few academics risk their reputations or careers by seriously searching for signs of alien activity. Even SETI, one of the most high-profile organizations engaging in this research, is often mocked or dismissed by scientists in the field. But, why? The sciences aren’t always reluctant to engage with speculative ideas. Some of the most fashionable theories in physics, such as supersymmetry, extra-spatial dimensions, and string theory, are all popular despite having no experimental basis. Compared to these concepts, the possibility of extraterrestrial life is incredibly grounded. The mere existence of Earth already provides strong evidence that life occurs. There are many reasons for this bias, but a key roadblock is cultural. The prevalence of aliens in popular media makes any inquiry into extraterrestrials seem like a sci-fi sideshow. Young scientists believe it’s more prudent to pursue grants, tenure, and academic prestige in fields like theoretical physics. And they’re right; this field is at the peak of its popularity thanks to well-funded and high-profile projects like CERN. Meanwhile, other questions are ignored. Yet, imagine if the search for alien life was given the serious consideration it deserves. What progress could we make if our brightest minds were encouraged to fully explore phenomena like ‘Oumuamua no matter where it leads? Many great discoveries in astronomy, from the heliocentric universe model to the hydrogen composition of the Sun, were ignored or suppressed by close-minded thinking. We should always work to avoid repeating that mistake in the future. ‘Oumuamua could be a probe or just extraterrestrial garbage. Gaze up at the sky on a clear night. Above you, thousands of stars twinkle through the Earth’s atmosphere. Amazingly, this shimmering array is only a small fraction of our galaxy, which is home to billions of stars. Beyond that, other galaxies contain billions more. The universe is expansive in size, but it’s deep in time, too. Recent estimates place it at more than 13 billion years old. Given these dimensions, it’s inconceivable that other life hasn’t arisen out there, somewhere, at some time. So, as the physicist Enrico Fermi asked in his famous Fermi Paradox: If there’s so much opportunity for life, where is everybody? Perhaps, thinking about ‘Oumuamua as an artificial object can shed some light on this mystery. The key message here is: ‘Oumuamua could be a probe or just extraterrestrial garbage. Let’s say ‘Oumuamua is actually a piece of extraterrestrial technology. The fact that we found it implies one of two scenarios. Either it was specifically sent to our solar system, which is flattering but unlikely. Or, whoever made it put so many objects into space that we had a high probability of stumbling upon one of them. The chances of us randomly crossing paths with an artificial object are very slim unless they are extremely common. To make this encounter likely, there would need to be about a quadrillion objects for every star in the galaxy. That’s one with 15 zeros behind it! Obviously, intentionally launching so many objects takes extreme dedication. However, there’s another option: ‘Oumuamua is space junk. From observing our own civilization, we know intelligent life can produce lots of waste. Currently, we make about two billion tons of waste per year. Most stays here on Earth, but some ends up in space. Right now, more than 13,000 manmade objects are orbiting the Earth. Some of these are satellites, but most are scraps and debris. We created this mess in mere decades with a tiny space program. It’s easy to imagine a vastly more ancient or expansive civilization having similar habits but at an immensely grander scale. If this were the case, it’s possible for the universe to be completely crowded with space junk in the same way that our oceans have collected massive amounts of our terrestrial garbage. Of course, our pollution may end our civilization before we get a chance to truly explore space. And it’s likely other civilizations have met a similar fate. If they did, could we still find them? We’ll ask this question in the next blink. We should examine the universe for all signs of life, both past and present. It’s three to four billion years ago. Here on Earth, a swirling stew of proteins and carbohydrates begin to mix and assemble into complex structures. Over time, these biomolecules develop metabolisms and start to replicate. Voilà, life! Now, when we search for extraterrestrial life, we take this familiar story as a starting point. We look for planets with similar conditions to Earth. That is, planets with similar size, temperature, or similar stars to orbit. It’s not a bad idea. After all, we understand life on Earth and can apply that knowledge to seek life elsewhere. But shouldn’t we be open to other possibilities as well? The key message here is: We should examine the universe for all signs of life, both past and present. Our current search for extraterrestrial life involves examining Earth-like exoplanets for traces of biological life. The problem with this approach is the narrow focus. Planetary systems akin to our Earth-Sun set-up are only a small percentage of possible arrangements. Moreover, looking for signs of active biomes will only find life that happens to exist at the exact time we’re looking at it. Given the age of the universe, this is a very unlikely overlap. A more effective approach would also seek different signs of life. This should include a broad range of evidence potentially left by civilizations, even ones that are long since gone. We can call this new branch of astronomy astro-archeology. This type of research scours the universe for alien life by looking for technology, chemical signals, and other physical evidence of activity in the same way terrestrial archeologists uncover past civilizations by examining fossils, ruins, and other detritus. For example, an astro-archeologist can examine exoplanet atmospheres for chemical signals that are only produced artificially. A planet rich in an industrial molecule like chlorofluorocarbons would be a sure sign of alien activity. Or, they could look for remnants of large-scale structures like Dyson Spheres. This hypothetical architecture consists of huge arrays of solar panels built around a star. It’s an obvious solution for civilizations seeking to harness power and would be fairly easy to spot. Expanding the scope of our search for extraterrestrials would require allocating more time and money in new programs and equipment. It’s a gamble, but one that would pay off. Think of it as ‘Oumuamua’s wager. Yes, taking the possibility of alien life seriously requires investment, yet the potential upsides are enormous. How would such a discovery change how we understand the universe, relate to each other, and handle our own affairs here on Earth? The shift in perspective could alter the course of our civilization. ‘Oumuamua should wake us up to the unlimited potential of humanity. OK, it’s finally happened. At last, humanity has detected definitive, unambiguous evidence of intelligent extraterrestrial life. Maybe it’s a radio communication picked up by SETI. Or, perhaps, it’s another interstellar object drifting through the solar system. Either way, it’s all over the news. In this scenario, are we ready to respond appropriately? Maybe; maybe not. Consider ‘Oumuamua’s wager. If we decided that Oumuamua was just a rock and continued as normal, we’d be caught off-guard. In contrast, if we took ‘Oumuamua as a possible artifact of alien life, we’d be ready for action. Maybe we’d have developed protocols for handling alien contact or have satellites in place to intercept the object. In short, we’d be more equipped to meet the future. The key message here is: ‘Oumuamua should wake us up to the unlimited potential of humanity. ‘Oumuamua has permanently left the solar system. We can’t catch up to it, and we can’t collect any more data about it. Even so, this unusual object has already taught us an important lesson about the universe and ourselves. If we allow that this visitor may be of alien origin, it shows that other civilizations are capable of amazing technological feats. And, if we learn to get along and cooperate, humanity may be able to reach similar heights of accomplishment. Right now, if we dedicated our resources to something like the Starshot Initiative, we could build a craft with properties similar to ‘Oumuamua. Using powerful lasers on Earth, we could accelerate these probes at speeds approaching the speed of light. There are many other fantastic technologies within our reach as well. For instance, the Szostak Laboratory is researching techniques to build synthetic biological life. More funding could help perfect the process. Combine these technologies with appropriate ambition and humanity could end up with a much brighter future. The Earth won’t always be habitable, and there's so much universe to explore. If we aim to, we could outfit lightsail probes with machines capable of replicating our DNA wherever they go. By launching fleets of these crafts, humanity could seed the universe and become a truly galactic civilization. These grand plans may sound fantastic. But, they are completely feasible with patience, dedication, and imagination. Consider this. In 2016, dozens of research facilities around the world coordinated their instruments to form a Earth-sized interferometer network. They trained their sights 52 million light-years away and managed to capture the first-ever picture of a real, existing black hole. This is just a small example of what humanity is capable of. We just need to be open-minded and try. Final summary The key message in these blinks: In spring 2017, scientists identified the first interstellar object ever detected and named it ‘Oumuamua. This object had many strange properties inconsistent with naturally occurring phenomena. It was oddly shaped, extra luminous, and moved in unexpected ways. It’s possible ‘Oumuamua is an artificially constructed lightsail and a possible artifact of intelligent life. Taking this possibility seriously can open up new paths for research and prepare humanity for a larger future. Additional music featured is 'Also Sprach Zarathustra', composed by Richard Strauss, made available under a Creative Commons license by Kevin MacLeod. Got feedback? We’d love to hear what you think about our content! Just drop an email to remember@blinkist. com with Extraterrestrial as the subject line and share your thoughts!