I walk outside after dark and can’t see the stars. Not in this bright town. Our own radiance obscures our view. Which is ironic, I suppose, but that’s where we are. A few stars sometimes manage to shine through. Sirius would be visible later in the year. Now, I should be able to see Alshain, but I can’t see it in all this scattered light. No one can, even though it’s right there, just above my building.
Oh, my. My building. Not just the place where I work, but the place where I was working then. Then being now, when we completed years of analysis and made our announcement. And I led the team. If this wins a prize, they might actually name this building for me. Like Michelson Hall, with its row of bronze disks marking the path a beam of light followed when Albert Michelson measured its speed.
I spent a lot of hours sitting in classrooms in Michelson, wondering what I’d gotten myself into at the Naval Academy. Wondering if I could make it through a physics degree. Even wondering what it had been like for Michelson as a nineteenth-century Midshipman, and then as naval officer and scientist. Looking back, it’s clear to me I drew some inspiration from him, from his youth, and the magnitude of his accomplishment. It made him the first American to win the Nobel Prize. I suppose he was a distant mentor, because here I am. And I still wonder just like I did back then: where is that beam now? A hundred and thirty-something light years away. It could have traveled to Alshain and back and to Alshain again in that length of time. The beginning of a conversation.
I don’t know if I’d ever get over it if they named this building for me. Or if not this one, the one that someday replaces it. Not because what we did wasn’t momentous, just that in retrospect it seems so simple. And what we learned, so sad.
The simple part is that we have it, the first evidence. All the data, all the analysis, all the proof. Tomorrow we’ll tell the world. Whether the world hears the message or not is a different story. This story—the story of our discovery—has come to an end. It began before I was born. It began with SETI.
The projects we call SETI—the Search for Extra-Terrestrial Intelligence—date back to 1960. Even before then, both Tesla and Marconi imagined this type of work. I’m sure neither of them appreciated it would be like searching for a needle in a haystack. From the outset of the modern project, when Frank Drake collected signals with a radio telescope in West Virginia, program administrators knew the challenge lay not in collecting signals. Collection was easy. Instead, the challenge lay in separating signal from noise. Data processing power was the key to discovering a signal in all the collected noise. Without noise, artificial signals would be easy to recognize. They would be repetitive, though probably irregular, and they would occupy narrow bandwidths. Some pattern, however faint, however unfamiliar, would surely differ from background phenomena in a way that would allow SETI algorithms to discern signal from noise. Yet year after year, they didn’t. Therefore more processing power was brought to bear.
In the late twentieth century, mainframe computers offered the muscle necessary to run complex noise-filtering algorithms, but they did so at great expense. To increase processing power without increasing expense, program administrators settled on the idea of distributed computing. They adopted the approach in 1999 when SETI enlisted idle desktop computers around the world. Volunteers signed on to let their machines run SETI algorithms during periods of low use. Each participant must have hoped the first string of alien text, the first line of conversation, or the first broadcast greeting from another planet might run through their computer, be detected, and vault the citizen-scientist to fame.
In addition to distributed processing, SETI developed methods to employ backyard satellite dishes as modestly-sensitive radio telescopes. This supplemented Project Argus, a SETI affiliate that coordinates a global network of small, amateur-built radio telescopes in an effort to achieve real-time coverage of the entire sky. The sensitivity of these collectors is as good as that of the Ohio State Big Ear antenna that detected the “Wow!” signal in 1977.
Dreamers with antennas and computers signed up for both of these programs. They joined hoping to hear an otherworldly Edison hollering “Mary had a little lamb” from somewhere out in space. Hundreds of thousands of volunteers provided hundreds of teraflops of processing power. Still, the needle, if there was one, remained in the hay.
In 2004, I worked with a team of graduate students who were good at discerning signal from noise in a different field of haystacks. Our field lay not in the sky but here on earth. We had a grant to examine audio recordings collected by drone aircraft. We intended to process the sound similar to the way operators of SOSUS arrays processed acoustic recordings to detect submarine signatures. Instead of detecting mechanical sounds in the ocean, we sought ways to capture conversations traveling through the air. We hoped to make it possible to glean intelligence with expendable, unmanned aircraft rather than costly, vulnerable human assets on the ground.
Our team designed an array of microphones attuned to the frequency range of the human voice. We employed simple filtering techniques to cancel out the 50- and 60-Hertz hum of electrical components, the thousand-rpm drone of the aircraft’s propellers, and the 10,000-rpm whine of its engines. We did all of this with technology as common as that found in the noise-canceling headphones many of us wear on long commercial flights. We canceled the noise and we listened for the signal, and we found no needles in the haystack. Undeterred, we believed in our purpose and our method, so we refined our techniques. I told the team to construct algorithms to attract likely data sets the way a magnet dragged through hay would attract a needle. I assured them this was how we would succeed. I was wrong.
Insight comes from unlikely sources. One evening during a dinnertime conversation of “Did-you-know?” and “Oh, yeah? Well, did YOU know?” that makes up part of my family’s mealtime ritual, my youngest son told the rest of us about early settlers moving west. “Do you know the last thing they did when they moved?” he asked. No one answered. “They burned their cabins.” He beamed as we sat wondering why in the world anyone would destroy their home, especially one they had built themselves through great expenditure of energy and precious resources. After a moment my son added, “To recover the nails.” I got up from the dinner table and walked to my computer to email my students. We didn’t need a magnet to attract the needle. To find the needle, we needed to burn the hay.
Within minutes, I had two responses. The first came from our resident naysayer. The Fun-Vacuum, we called him, for his ability to deflate many a sense of elation with his irritating voice of reason. “A relatively dense needle will sink into ashes and remain hidden,” he wrote. He could even suck the fun out of a metaphor.
Seconds later, our unconstrained freethinker responded. “Burn the hay and ignore needles. Look for spikes instead.”
So we ignored the noise, ignored metaphorical needles, and wrote an algorithm for spikes. Literally, spikes in signal intensity. We ignored the noise through time compression of our samples, burning away what we had once examined for snippets of conversation. What remained was a monotonous undercurrent of sped-up noise, punctuated by spikes of sound. In previous analysis, these spikes had not even caught our interest because they weren’t what we were looking for. They weren’t voices. Yet now they stood out as clearly as iron spikes lying in the ashes of a burned cabin. We picked them up, turned them over, examined the recordings in real time, and recognized that the spikes were manmade. They were as manmade as angry shouts and just as charged with emotion, but they weren’t voices at all. They were gunfire.
Our ability to detect gunfire in recordings captured by drone aircraft was a first step. In the early recordings we analyzed, the gunfire led us to detect voices associated with skirmishes. That detection, and subsequent analysis of actual voices captured by test drones in real-world conditions, helped us refine our techniques. We improved both our detection and our analysis. At the same time, drone technology advanced considerably. Now drones are smaller, quieter, more agile than ever. They can go places and record sounds that we would not have thought possible a decade ago. As a result, voice detection has become routine.
We continue to make advances, and we have a voracious customer for the product of our efforts. I can’t describe the current state of this technology in too much detail, nor can I comment on its uses. However when you are talking with a partner in a pastoral setting with no one else in sight, and you feel free to speak your mind or your heart amidst birdsong and the whisper of wind through the trees, be romantic and brash. Feel free to strip naked and run through the grass. You may be seen, but don’t worry about that. Just be careful what you say.
But I’m getting off track. When we think of gunfire, it’s useful to consider its iconic forms. The report of a rifle, the boom of a shotgun. The roar of cannon, the whine of a bullet, even the unheard sound of the one that gets you. We know a burst of automatic weapons fire, the pop-pop-pop of a drive-by. We also know iconic shots in history. In 1775, a colonial soldier fired “the shot heard ‘round the world.” And one hundred seventy years later, the United States set off what we could call “the shot heard across the stars.”
The EM pulse from the blast at Trinity Site in New Mexico was of an intensity that dwarfed radio transmissions of the day. To a radio telescope observer within a few light years of earth, it would have stood out from interstellar noise like a spike rising from a background of unremarkable ash. Anyone in this part of our galaxy may yet hear that shot, as well as the many that followed. My team and I heard just such a shot. To our astonishment, it was fired by someone else.
The SETI Project has done remarkable work. Since its inception, it has considered thousands of spurious signals emanating from near and distant sources in space. All of those have been examined and discounted. The “Wow!” signal and all the other tantalizing leads have fizzled. Yet the project has compiled an extensive collection of recordings. Of noise, really, at least by the standards of the time. However the collection provides a valuable archive, full of potential for further exploration. It is a vast field of hay raked and shocked into neat stacks awaiting someone who wants to search for needles. Or spikes.
Public funding for SETI ceased in 1994. Private funding has sustained it ever since, subject to the vicissitude of donors. The project has survived on a shoestring budget. In contrast, my project to enhance the detection capabilities of unmanned aircraft, deemed crucial to national security, remains well funded. In addition, our work has resulted in patents that have produced a significant stream of income. As a result, we are flush with funds. It was a non-issue for us to come up with enough money to offer a generous donation to SETI in return for a look at its archive. Its director granted our request even though we were out of our element entirely. We must have seemed like some rich agricultural historian offering an irresponsible but welcome donation to an art museum in exchange for a closer look at Van Gogh’s haystacks.
In 2011 my team began to examine SETI data, but not before the Fun-Vacuum expressed reservations. In dismal emails, he wrote, “Our algorithms are written for base frequencies in hundreds and low thousands of Hertz, not Megahertz and above. Their scalability is non-linear…” And, “Cultural phenomena that would constitute locally-intense events are unlikely, whereas your metaphorical spikes are relatively common in crude frontier cabins.” Yet despite his stilted pessimism, the naysayer adapted our algorithms with alacrity. In a matter of weeks, we were processing SETI data. In a month, we heard gunfire.
I can’t help marvel at the technological evolution that’s evident here. Someone decades ago wrote programs on punch cards, recorded them on magnetic tapes, and ran them to detect Cold War submarines in sound captured by undersea microphones. My team adapted that code to detect sounds of interest intercepted by remotely controlled aircraft. We stored the modified code on compact disks. Just a few years later, it served as the basis for still newer code which we now store on flash drives. We run it to scan interstellar noise as we look for signs of intelligent life. That just amazes me. But this story is not about human technological evolution. No, this is the story of someone else, a people with a history all their own, and we heard them.
First, we heard their gunfire. Or at least a shot. Beginning with the earliest SETI records, we scanned more than twenty years of data in a few weeks. We soon detected a spike. Captured in 1981, the spike resembled the electromagnetic burst one would expect to see from an uncontrolled fission reaction. Spectral analysis indicated it involved Uranium-235. This captivated us, because fissile reactions of U-235 are rare in nature.
The signal that included our spike emanated from the region of the star known as Alshain. Astronomers catalog it as the second-brightest star in the constellation Aquila, giving it the designation Beta Aquilae. Aquila, the eagle, lies along the Milky Way just north of the celestial equator. It is visible during the summer. While Alshain shines in our sky as part of Aquila, an observer in that star system looking in our direction would see Sol, our own sun, as part of Canis Major, the dog that accompanies Orion the Hunter. To the residents of the third planet of Alshain, our sun would form the ear of the dog. And sure enough, here we are, listening.
Alshain lies forty-five light years from our solar system. Given that distance, and considering the date on which the signal arrived at earth, it’s easy to refer to the earth-year in which specific events on the other planet transpired. As we consider time and measures of time, it is interesting to note that the planet Three Beta Aquilae to which we localized our spike has a day lasting twenty-nine hours, and it completes an orbit of Alshain in two hundred ninety-eight of its days. Although the distribution of daylight hours differs from ours, the amount of time in a year on that world differs from the amount of time in one of our own years by only two hours. A remarkable coincidence? Of course it is. And it’s one of many facts available for further consideration.
The signal we detected left its home planet in 1936. Our team saw another spike in SETI data from later that same year, and it also emanated from Three Beta Aquilae. This spike bore characteristics very similar to the first, down to the spectral lines from a fissile reaction of U-235. Intensity was slightly greater, but not remarkably so.
We didn’t locate other spikes in SETI data until more than a year later. Logs of the source data collected during the intervening period reveal that Beta Aquilae, or Alshain, was not included in surveys during most of that time. However when we did detect another spike, it came from Alshain. This third spike occurred in 1941. Its intensity was noticeably greater, although within the same order of magnitude of the first two. A key difference, though, lay in spectral lines. They indicated a fissile reaction of Plutonium-238. If we can draw an inference from mankind’s own experience, it suggests we are seeing evidence of technological evolution. This particular evolution is unfortunate.
History repeats itself, even within the microcosm of our little project. In our work with drone aircraft, we first looked for spikes of sound as a proxy for human activity. In the data close to the gunfire captured in our audio recordings, we sharpened our analysis until we detected human voices. Eventually we refined our techniques enough to detect voices outright, without the need for gunfire to draw our attention. We followed a similar progression in our analysis of SETI data.
Our goal, and the goal of the SETI project from the outset, was detection of a modulated radio signal. A carrier signal, laden with whatever information a broadcaster chose to impart. We refined our computational routines to the point that we could detect the signals we sought, but the sensitivity of our algorithms was not the only limitation in detecting radio transmissions. The intensity of the broadcast and the sensitivity of our hardware posed physical obstacles to detection.
A basic assumption of early SETI work was that limitations in detection would enable us to receive only a strong, overt signal explicitly transmitted for the purpose of contacting an intelligent listener. What mattered more than our ability to recognize a signal from an intelligent source was our technological ability to detect it at all. Assuming the use of the most sensitive receivers available, detection is limited by the “effective isotropically radiated power” of the transmitter, or EIRP. That’s the amount of power an antenna would have to emit to produce a signal observable by a receiver of sufficient sensitivity. Our detection of a deliberate transmission depended on having receivers sensitive enough to receive and record signals of reasonable EIRP, weakened by spherical spreading over interstellar distances. Technical enhancements and improvements in receivers now give us the ability to detect a signal transmitted with an intensity of less than one gigawatt EIRP transmitted within two hundred light years. But that sensitivity was much lower until quite recently. This means if anyone was saying anything before now, we probably missed what they said.
About six years ago SETI completed a significant upgrade to the sensitivity of its detective equipment. Right after the upgrade, the project captured a large quantity of data from the region of Aquila. A few weeks ago our team processed that data, using algorithms refined beyond the point of detecting spikes. What we found thrilled us: a modulated radio signal carrying evidence of intelligent civilization. That still amazes me. We had realized the SETI program’s goal—and one of mankind’s dreams.
While we couldn’t translate into words what we heard on audio renderings of the signal, what we did hear and see in the data was obvious. We saw an embellishment of the carrier frequency repeated at intervals throughout the twenty-nine hour day of planet Three Beta Aquilae. The sounds remind me of the fanfare that was prelude to the BBC World Service broadcasts I listened to on shortwave radio as a young man. It was the Lilliburlero, the signature introduction that played after tones counted down to the hour and the solemn announcer said, “THIS is London.” Maybe the network still does that, I don’t know. Anyone who has heard it knows exactly what I mean. Or maybe people are more familiar with the eight-note tune we hear each afternoon on the way home from work at the beginning of “All Things Considered” on NPR. That is exactly what we have in these recordings from the third planet of Alshain in the constellation Aquila. We have the news. Without a Rosetta stone we may never understand the broadcast, but it’s the news.
I suspect the news was grim. We detected bursts of electromagnetic radiation from Alshain’s third planet. The bursts bore characteristic signs of explosive fissile reactions. The first blasts involved Uranium-235, while other early explosions involved Plutonium-238. Blasts followed a semi-regular pattern consistent with the sort of nuclear testing the United States and the Soviet Union engaged in during the mid-twentieth century. Then, after about seven years of fission explosions on Three Beta Aquilae, we saw evidence of a much more intense EM pulse. The explosion bore signs of a fusion reaction produced by a hydrogen bomb. It even had the telltale tritium hyperfine line at 1516 MHz. SETI researchers have long regarded the tritium frequency as interesting because the isotope is rare, and because emission may indicate nuclear fusion carried out by a technologically advanced civilization. Looks like they were right.
The fusion explosions we detected continued in a regular pattern, as did further fission explosions. Peak intensity of occasional blasts increased significantly. The more routine blasts settled at five distinct levels. Team members draw different inferences from this observation. A prevailing thought is that these levels represent mass-production tactical and strategic weapons of prescribed yield being tested as part of a weapons development program. Explosions involving these devices continued through about fifteen years’ worth of data, until they stopped.
The EM pulses we detected left us with no doubt. We were observing artifacts of an advanced civilization. We were fairly certain it had not directed a strong signal our way, although there were gaps in our data from periods during which no observations of the region around this star had been recorded. The data that contained the news broadcasts excited us beyond our wildest expectations. We had been at this for mere months at that point, having reprocessed all SETI data ever captured using detection algorithms that we continually refined. When we made a significant improvement, we re-ran data we had run just days earlier. We were no longer looking at the entire SETI archive, just the data for Beta Aquilae. The nuclear tests stopped, we endured a few days of signals captured on older receivers, and then we processed data captured after the 2006 upgrade. Right away we detected the flourish of music that I am sure came as prelude to a program of some type. I would not have been surprised to hear, “THIS is Alshain.” Instead, we heard another shot.
Two data-processing days after the radio signal we call the News Program, we detected a fission explosion of modest intensity. We wondered if explosions like it had been taking place all along and had simply fallen into gaps in the recorded data. Or maybe the blasts had been suspended under a test ban treaty. Whatever the case, we had not seen spikes in several years’ worth of data, and now we found one. Meanwhile, we detected other news programs. We recorded enough to see a pattern emerge. And we recorded another fission explosion. Then another.
One week after processing the first data records captured with equipment installed in the upgrade, we detected a fusion explosion. An hour’s worth of data later, another. Thirty minutes later, we recorded the first of four hundred thirty-eight large fusion explosions that detonated within a twenty-minute window. Then silence, until we detected one lone transmission.
The transmission that followed the period of intense explosive activity was a modulated carrier signal bearing a message that repeats at precise intervals. Its periodicity led us to conclude that it comes not from the third planet of Alshain, rather from a moon of that planet. The transmitter sits on the side of the moon facing away from the planet, shielded from all of the EM bursts that would have rendered ground-based and orbital transmitters useless.
Today, after transmitting continually for six years, the modulated signal still emanates from a moon of the third planet of Alshain. We see it routinely in the data, unaccompanied by other transmissions of any kind from that planetary system. The signal carries only a single phrase, repeated around the clock. Beyond any doubt the transmission is automated, not live.
The automated transmission may be all that remains of a civilization that flourished forty-five light years from here. Members of its society might have looked up into the night sky toward Orion and Canis Major and seen an unremarkable star above Sirius forming the point of the great dog’s ear. The observers may have wondered if life existed on planets orbiting the stars they saw. They could not have known that by now, signs of our civilization would be reaching theirs. And even if they had guessed or speculated that someday they would detect us, they would not have guessed that the first person to know about them would tell our world about the inhabitants of Alshain-3 in the past tense, reporting that evidence of their civilization resides now only in recorded data. Live evidence sped past us years ago. It is already light years away and receding, fading as it expands. It will not be detected again.
We may never know what the remaining transmission from Alshain says. I think it calls out from the collapsed universe of its own world to the expanse of neighboring space, asking a single question over and over again. It’s the same question humans have wondered since we first looked up, since we first began to listen to the stars, as attuned as a dog who has cocked an ear to the cry of an eagle. We ask, “Is anyone there?”
I remember walking out of class onto the plaza between Michelson and Chauvenet Halls at the Naval Academy. No matter how much of a hurry I might have been in to get to my next class or to noon meal formation or to go on liberty with my friends, I always looked at the row of brass disks set in the conglomerate paving tiles. I let my gaze follow the path they memorialized. When the crowd of midshipmen and tourists was thin, and certainly if I was alone, I would walk along the line defined by those disks. I followed the path of a beam of light ignited by my distant mentor, and I wondered where it led, where its photons were at that moment. They’re out there somewhere, faint and undetectable. But there, like the evidence of Alshain. Alshain’s photons are the light of mentors, gone forever with the lessons they might have shared.
This story first appeared in “Into the Ruins,” Spring 2020 – Issue 15.