Today was the day. For over a century, we had been anticipating it, dreading it, praying for it. Hospitals, authorities, and schoolchildren in their classrooms waited with bated breath; they aimed missiles at the sky from every continent. A coalition of leaders from each nation, every creed, sat together in nervous silence, their eyes on satellite feeds and news reports. Their parents and their parents’ parents had grown up in the waiting world, knowing the day was rapidly approaching. And now it was here.
One hundred years ago, we received a transmission from deep space, unintelligible but undeniably intelligent in origin. It took us a year more to decipher it, passing it between countries and scientists, the general public and supercomputers, looking for patterns, for a breakthrough. When they had finally decoded it, it was a future date, announced by a mathematical description of the position of the stars in reference to the center of the galaxy. The date was set, and the countdown began.
At first, there was talk of impending Armageddon, of the aliens coming to destroy us all, or at least to cull the unworthy. Others waited eagerly for our salvation, when the extraterrestrials would lift us from our primitive, Earth-bound ways. Many simply did not believe; they called the whole thing a hoax to frighten us into obedience, and ignored or criticized the approaching day. Scientists and curators of science-fiction remained eager but skeptical, unsure if the aliens spelled doom or hope, or something in between, or if they would even arrive at all.
But even the most unconvinced among us could not deny the nervous energy that settled over the globe as the stars aligned in perfect accordance to the century-old mathematical message. We had been monitoring the solar system, satellites and telescopes and radar disks turned both towards the sun and out to the far-flung reaches of the Jovian worlds, looking for any sign of invasion. Many doubted we would see them before they are ready to make themselves known; with the technology to travel between the stars— so far beyond anything we as humans could achieve— surely they could hide themselves from us if they desired.
The first shadow appeared over South America, cloaked in the clouds, indistinct but unmistakably unfamiliar. The others followed, shifting in and out of sight, hovering over epicenters. The panic began, the prayers and the preparation of weapons. Then their message played, hijacking every television and radio and SmartCar and phone, repeating in every language that had been broadcast into space throughout the decades. Of course, they’d had over a century to study us, to decode our signals, to devise a method of communication.
“Hello,” they said, the greeting echoing from every device in every human dialect. “We come in peace.”
Looking for Life
Life beyond Earth has fascinated the imaginations of artists, writers, filmmakers, and creatives of all sorts for over a century. We imagine unknowable cosmic beings that dwell beyond our ability to comprehend, sentient races with whom we can communicate, collaborate, or wage war, and strange, unfamiliar plants and animals undergoing their own evolution. In particular, invasions or visitations of Earth (Signs, Independence Day, The Arrival) and interaction of humans and alien culture together in space (Star Trek, Star Wars, Guardians of the Galaxy) seem to capture our interest, imagining how we might fight back against or befriend extraterrestrial lifeforms. In both cases, the focus is not solely on alien life, but on sentient life, with whom we can understand, and be understood by. Far more than alien microbes in a sea beneath Europa’s icy shell, we desire to find intelligent life among the stars.
Creatives aren’t the only ones with this vision, either. The SETI (Search for Extraterrestrial Intelligence) Institute is a coalition of over one hundred scientists on the hunt for sentient alien life, backed by NASA and numerous research institutions. SETI uses huge telescope arrays, radio observatories, and experimental new technologies not only to hunt for signs of life, but to advance our understanding of physics and the universe. There is currently no telescope large enough to look directly at potentially-habitable planets orbiting distant stars (and most likely never will be), so SETI studies radio waves and monitors lasers emitted by pulsars, hoping to find indirect signs of something artificial radiating from distant solar systems.
But what makes NASA scientists and countless researchers from around the world so certain there’s something to find? The answer is a mix of math and theorizing that has been many decades in the making— the Drake equation. This famous formula, conceived in 1961, attempts to predict the amount of “transmitting societies” in the Milky Way galaxy, meaning societies not only capable of interstellar communication (such as with radio or light), but who are also choosing to create such signals. Few variables in the Drake Equation have definitive answers (such as the rate of formation of stars suitable for life), as most are based on educated speculation (fraction of planets that develop life, and fraction of those planets that develop intelligent life, for example.) However, considering the immense number of stars in our galaxy, even conservative estimates put the number at twenty intelligent civilizations, while optimistic interpretations say it could be over fifty million. The true answer is probably somewhere in between, but even if life is much rarer than modern scientists believe (that is, life itself is common on a galactic scale, and therefore intelligent life may also be more common than formerly believed), it is hard not to think that somewhere else in our Galaxy is— or was— a society that transmits signs of their existence into space.
Why haven’t we found it yet?
If even pessimistic estimates say there are multiple detectable civilizations in the Milky Way, the natural question is, why haven’t we detected them? The easiest and most mathematical answer is that space is big. The Milky Way is 50,000 light years across, meaning that even if there is or was transmitting species sharing the galaxy, it may take thousands or tens of thousands of years for any sign of them to reach Earth (which has only been broadcasting for fifty some-odd years.) Of course, transmissions from the early days of television and radio have already reached several thousand nearby stars, and while they would require massive antennae to detect, alien civilizations could hypothetically already be aware of our existence. So, while distance is certainly a concern, the size of the Milky Way alone does not necessarily preclude us from finding intelligent life in our local star cluster.
On a broader scale, the conflict between a lack of evidence for extraterrestrial life and the high estimates for its existence is called the Fermi Paradox. There are innumerable potential responses beyond the size of the galaxy to physicist Enrico Fermi’s famous question— “where is everybody?” Many of them are highly theoretical in nature, and range from the idea that sentient civilizations are fated to last for only brief periods of time, to the thought that they are all hiding from us, either for self-preservation, or because humanity has not been deemed “worthy” of contact. Other theories— particularly the sort that interest SETI— are that we have not determined the proper way to detect or decipher alien transmissions. While it is essentially impossible to “prove” that Earth is being blacklisted by an interstellar federation, it is entirely plausible that nearby societies broadcast with a technology currently foreign to us, and we have simply not devised the best way to listen in. Similarly, signals that we have already detected from space may be too alien in their meaning and function to be deciphered as artificial. Scientists at SETI hope to better understand the origin of these interstellar signals, and to continue devising new ways to probe the skys for transmission methods that may be intelligent in origin.
Meeting the Neighbors
First Contact with alien life is a major focus in many speculative stories, depicted in varying levels of difficulty and strangeness, from humanoids that learn our language easily, to entities that we are barely able to understand with forms of communication that cannot be deciphered. The truth is likely somewhere in the middle— having undergone their own few billion years of evolution on a world far different than ours, it’s unlikely that aliens will resemble anything like humans. But they will probably have some similar senses to ours, as all life needs a way to interpret and interact with its environment, especially a species capable of spacefaring or transmitting. So while we may not physically recognize our neighbors, all hope is not lost for establishing some form of communication between us.
In 1977, NASA launched two Voyager spacecraft to explore interstellar space, but each of them carried something else, as well— the “Golden Records”, gold-plated phonograph disks containing sounds and images intended to inform extraterrestrials about the human race. In 2010, author and artist Trevor Paglen compiled one hundred photos from around the world and devised a nearly immortal “time capsule” to keep them in before they were taken to orbit aboard the EchoStarXVI, calling his project “The Last Pictures” and intending for them to be discoverable by future visitors after the end of the human race. But while these sentiments are admirable (and perhaps even effective someday— who knows?) they fail to consider that aliens may not have the same sensory organs as we do, namely, eyes or ears. While it certainly makes logical sense that a space-faring species would have some sort of light-sensing organ resembling eyes, it is by no means a guarantee (perhaps they make up for it with a sensory organ that we cannot even conceive of); even here on Earth, there are species that navigate and live quite effectively without the use of eyes. Perhaps these aliens communicate with a highly specialized sense of smell, and have no concept of “sound” or “spoken language”. What do we do then? The most generic way to converse with an alien would likely be through the use of touch, as they would have to have some sort of tactile, interactive organ in order to have built a civilization and crossed the stars. But adding braille to our spacecraft will not make them immediately intelligible to extraterrestrials— even an alien with eyes would likely be confused by the Golden Record’s drawing of a male and female human, and touching a relief of a human body won’t be much clearer. There is really no way to ensure our probe emissaries are able to properly convey our messages to anyone who might find them— conservation will have to be undertaken by very patient and very willing members of both species.
This issue, however, is unlikely to ever arise (as timely interstellar travel is far beyond our current level of technology) and is not the primary focus of organizations such as SETI; there is a significant difference between mutual contact with alien species and simply discovering signs of their existence. While an alien spacecraft coming across the Voyager probe and making their way, physically, to Earth is an exciting prospect, it is much more likely that we will detect transmissions from an alien world thousands of light years away. The question that follows then is: how do we understand it? Should we happen to overhear any alien radios, it would be far beyond our understanding. Humans alone have over 7,000 languages, some of which remain untranslated today. Zipf’s Law, a mathematical law about the frequency of certain words in a sample, may be able to identify that a language exists in a transmission— but not what that language is saying. A more intentional message may be a little easier to decode; scientists have theorized that an intelligent race may use mathematics to convey messages, in which case, we may stand a chance of identifying patterns in the transmissions. And then we have to reply— it will take our message between decades to thousands of years to arrive back at the source, making consistent back and forth communication anywhere from painfully slow to impossible. There’s no guarantee that the civilization that sent the transmission will even still exist to receive our response. Because of this, we will likely never “talk” to aliens directly, but rather discover signs of their existence, and send some of our own out into the void for others to someday find.
Could we handle First Contact?
Briefly setting aside how unlikely it is— unlikely things happen every day— how would our world change with First Contact? The only thing we can know for certain is that nothing would ever be the same. Some people claim that the discovery of aliens would dismantle many organized religions, while other religious people disagree, saying that aliens do not violate their faiths, and we should greet extraterrestrials as our equals and friends. If aliens came to Earth looking for resources (or even just came in peace), some people would no doubt react with literal xenophobia, attempting to drive away the strangers. Others would try to invite them to join us on our planet, no matter how intimidating they appeared. Would the arrival of extraterrestrials better unite us as a single human race, setting aside our differences and conflicts, or would it only serve to divide us further? As a species, we have proven ourselves capable of both incredible cooperation and devastating destruction, and it’s hard to know how we would rise to the occasion of contact with a race so different from us.
Finally, it’s worth considering that any alien species capable of visiting Earth directly would be far more technologically advanced than us, able to travel between stars at faster than the speed of light. So maybe we won’t have a choice in First Contact at all— if extraterrestrials capable of interstellar flight want to invade Earth, adopt humans as their wayward children, or make crop circles and skylights with motivations beyond our understanding, humanity will not be able to stop them. But, at the same time, I don’t believe we should fear colonization by a violent alien race; just as humans explore the stars out of curiosity for the universe beyond our own planet, other species will likely be just that— intrepid explorers. Perhaps in human existence we will meet fellow curious astronauts, or pick up the signals they’ve been transmitting out into the endless vacuum of space. Maybe we never will, and only after our society has vanished will our radio remains be stumbled upon by another species. It’s impossible to predict where, when, or how we will make contact, but the math says that somewhere in the Milky Way there is another intelligent civilization; all we have to do is find them.