Why the Wow Signal Lasted 72 Seconds

0:00You're listening to a podcast right now, driving, working out, walking the dog. If you're in a podcast, chances are you have something to say too. With RSS.com, starting your own podcast is free and easy. Upload an episode and we distribute it to Apple Podcasts, Spotify, Amazon Music and more. Track your listeners, see where they're from, and start earning from ads just like this. If you've been thinking about starting a podcast, this is your sign. Or your new podcast for free today at RSS.com. In August 1977, a radio telescope caught this just roaring, deafening signal from Deep Space. Yeah. And it lasted exactly 72 seconds. Right. Exactly 72 seconds. And it looked completely identical to the mathematical prediction of an intentional alien broadcast down to the, you know, the precise frequency. But then it just vanished. Vanished. Yeah. For decades. So welcome to the deep dive. Our mission today is taking a single comprehensive Wikipedia article and extracting the absolute

1:03most mind-bending details about one of the greatest modern mysteries of space exploration. The wow signal. The wow signal. And for you listening right now, if you love cutting through the noise to get straight to the mechanics of an anomaly that just defines all standard explanations, well, this is your masterclass. It really is. And looking at your backdrop right now, the visual perfectly sets the tone here. We have these retro 1970s computer punch cards. And they're seamlessly fading into these really expansive modern star charts. Yeah. I love it because we are standing right at the interception of somewhat primitive clunky 1970s computing and incredibly vast cosmic mysteries. Right. I mean, it is the ultimate cold case of astronomy. It's a single data point, so physically perfect, yet so frustratingly solitary that it has kept astrobiologists just agonizing over the data for nearly half a century. So let's establish the scene. It's August 1977. We are at Ohio State University's radio telescope, which was affectionately nicknamed Big Year. Big year, yeah.

2:04And a volunteer astronomer named Jerry M.N. is reviewing the data. And back then, you know, reviewing data wasn't looking at a sleek monitor. Oh, no, not at all. It meant physically perusing massive stacks of continuous form line printer paper that was just spat out by an IPM 1130 mainframe computer. Right. Just rings of it. So he's looking down at these endless columns of alpha numeric characters. And he sees a string of text so shocking that he grabs a red pen, circles it, and actually writes the word wow in the margin. The literal margin notes of history. Exactly. Okay, let's unpack this. The text he circled notoriously reads as 6EQUJ5. And we really need to clear up the biggest public misconception right away here. Yes, please. Because this isn't a cipher, right? It's not a secret alien alphabet we need to translate. It's, um, it's just a volume knob. That's a perfect way to put it. Right. Like the system measures signal to noise ratio. And when the volume gets dangerously earshatteringly loud, it literally runs out of numbers one through nine and just switches over to letters.

3:05Yeah. The measuring system adopted for this specific experiment was incredibly rigid. Like a blank space on that line printer paper just meant the intensity was normal, ambient background noise. That's static of the universe. Exactly. Between zero and one standard deviation above the baseline. The numbers one through nine meant it was one to nine standard deviations above that noise. But if a signal one above nine, the computer switched to the alphabet. So A meant an intensity of 10 to 11, B meant 11 to 12, and so on. Which means tracing that alphabet all the way up to you puts us at an intensity of 30 standard deviations above the background noise. Yes. I mean, that is a massive spike in radio energy. It is a deafening roar. And the mechanical rhythm of how this was recorded is, well, it's vital to understanding why it's so compelling. How so? So the bigger telescope sampled the incoming radio signal for exactly 10 seconds. Then the IBM computer took exactly two seconds to process that sample and physically strike

4:06a single character onto the printout. Okay. So every character is a 12 second window. Right. Put down that specific column six EQ, UJ5, you're looking at a 12 second pulse beat by mechanical beat. Wow. It captures a signal that rises dramatically out of the background static, hits this unbelievable peak of intensity at you, and then steadily fades back down into the noise. Here's where it gets really interesting. Because knowing the mechanics of the code is one thing, but allowed noise shouldn't immediately make a rational astronomer think of aliens. No, it shouldn't. Physical anatomy of the signal is what makes it so legendary, specifically the duration. It lasted for exactly 72 seconds. Now I'm stuck on this 72 second window because like if I'm in advanced civilization trying to contact another world, I'm leaving my transmitter on all year. You think so? Yeah. I'm broadcasting continuously. Oh, yeah. Well, 72 seconds. Couldn't it just be a random Earth radio broadcast sweeping past the telescope or like a passing military plane?

5:07See, that is the logical first assumption. But the 72 second duration is actually the absolute strongest piece of evidence against it being an Earth-based broadcast. Wait, really? How? We have to look at the physical engineering of the bigger telescope. Unlike modern radio telescopes, you know, the massive dishes you see tilting and pivoting to track an object across the sky, bigger was essentially fixed to the ground. Oh, right. It was a transit instrument. Exactly. It could tilt slightly up and down to adjust its altitude, but to scan across the sky from east to west, it literally relied on the rotation of the Earth. So it was just staring at a fixed trip of the sky, letting the Earth spin through the panning. You got it. And because of the specific width of the telescope's observation window, combined with the exact rotational speed of the Earth, a fixed celestial object in deep space would stay in big years view for exactly 72 seconds. Wow. Not 71, not 73. If a continuous stationary signal was beaming toward Earth from a distant star system,

6:08the telescope would pick it up as a gradual increase in volume for the first 36 seconds as the telescope's beam rotated into the signal. Right. You would peek right in the middle and then display a gradual decrease for the final 36 seconds as the telescope rotated away. So 36 seconds up, peek at the U and 36 seconds down. It perfectly maps to a stationary point source in deep space. It is flawless. When a passing airplane or a satellite in orbit moves independently of the Earth's rotation, they would streak across the observation window much faster, or they'd linger longer, which would totally destroy that perfect 72 second bell curve. That makes corals sense. And the frequency of the signal is just as important as the shape of it. The signal came in at exactly 1420 megahertz. Yes, the hydrogen line. Exactly. Now, back in 1959, physicists Philip Morrison and Giuseppe Coconi wrote a seminal paper predicting that if an advanced alien civilization wanted to communicate across the galaxy, they would inherently use this exact frequency.

7:09And the physics behind that choice are fascinating. It's not arbitrary at all. 1420 megahertz is the natural emission frequency of neutral hydrogen, right? Yes, which is the most abundant element in the entire universe. Right. If you look at a neutral hydrogen atom, you have a proton and an electron, both possess a quantum property called spin, and occasionally the electron flips its spin direction. When that spin flip transition happens, the atom releases a tiny amount of energy in the form of a radio photon with a wavelength of exactly 21 centimeters, which equals a frequency of 1420 megahertz. Exactly. Any technologically advanced civilization anywhere in the universe would know this fundamental rule of physics. They absolutely would. It is a universal constant. So it kind of operates like the universal maritime distress channel. Oh, let's get analogy. Like, if you are a ship out on the ocean and you want to hail another vessel, you don't just pick a random radio frequency and hope someone is listening. Yeah, of course not. You broadcast on the dedicated channel that you know every other sailor is already actively

8:10monitoring. Right. And what's fascinating here is that on Earth, that specific 1420 megahertz frequency is actually a globally protected spectrum. Really? By international agreement, it is reserved exclusively for passive astronomical research. Terrestrial transmissions, so military radar, commercial radio, television broadcasts, they are strictly forbidden by law from broadcasting anywhere near that frequency to prevent interference. Wow. So you have a signal that precisely mimics a deep space origin, lasts exactly the length of time a deep space object should and comes in on the one universally protected frequency that physicists predicted an alien civilization would use. Everything about its physical profile just screamed extraterrestrial. Absolutely. But I mean, if we have the perfect signature and the perfect frequency, why didn't we just point every dish on Earth that that's bought in the sky and start talking back? Well, that's the tragedy of it. Yeah, this leads us directly into the geographical ambiguity of the signal, which has to be the

9:12most agonizing data limitation in modern astronomy. We literally didn't know exactly where to point. We didn't. And it comes down to a quirky design limitation of the Big Year telescopes data processing. How did it work? Big Year utilized two feed horns. Think of them as two separate antennas sitting side-by-side, pointing in slightly different directions in the sky, following the Earth's rotation. To filter out background static, the receiver system was designed to electronically subtract the signal of one horn from the other. Right. That makes sense for cleaning up the data. Yeah, but the problem is the wow signal hit one of the feed horns, but not the other. And because the computer only recorded the difference between the two horns to save processing power, it was physically impossible to determine which of the two horns actually received the incoming signal. Oh, no. So we had the declination, the up and down coordinate locked in perfect. Yeah, yes. But for the right ascension, the side-to-side coordinate, we were left with two entirely separate, non-overlapping regions in the constellation Sagittarius.

10:15Exactly. It's like knowing a screen came from the fifth floor of an apartment building, but because of the echo, you don't know if it came from the apartment on the far left or the apartment on the far right. And you're just staring at two doors, completely paralyzed. But astronomers didn't just give up. Let's fast forward to the modern day, because our mapping of the cosmos has improved exponentially since 1977. Oh, definitely. In 2022, an incredible paper was published in the International Journal of Astrobiology. Researchers utilized the Gaia satellite database, which provides spectacularly precise 3D maps of our galaxy to look at what is actually sitting inside those two specific antenna-pointed coordinates. And they found something, right? They identified three likely sunlight stars. And one of them is a prime candidate, a star designated 2MASS192819822640123. Quite a catchy name, right? But it's perfectly situated about 1800 light years away. And it possesses a temperature, a radius, and luminosity incredibly similar to our own

11:17sun. It aligns brilliantly with theoretical estimations of where an intelligent civilization might evolve. So we finally had prime targets. But the silence has been deafening. Yeah. I mean, the follow-up efforts to find this signal again have been massive. They span decades and utilize increasingly powerful technology, like Robert Gray searched for it in the late 1980s with the meta-array at Harvard. He tried again in the mid 1990s with the incredibly sensitive, very large array in New Mexico. And they didn't stop there. Right. As a direct response to that 2022 discovery of the sunlight stars, the breakthrough listen project pointed both the massive green bank telescope and the Alan Telescope array right at those specific stars for a highly coordinated search. They scanned for hours. And they found absolutely nothing. Nothing at all. This raises an important question about how we validate anomalous data. Douglas Vakosch, the president of Medi-Messaging Extraterrestrial Intelligence, makes a crucial point about this. What does he say? In the realm of science, a discovery isn't truly a discovery unless it can be replicated.

12:22Without replication, without being able to point a telescope at a coordinate and measure the phenomenon a second time, the wow signal has very little scientific credibility as a confirmed alien broadcast. So a one-off event, no matter how flawlessly it aligns with our mathematical predictions, is just an agonizing anomaly. Exactly. So what does this all mean? Since science demands replication, researchers have spent decades fiercely trying to prove it was just a natural astronomical glitch or some terrestrial error. Oh, yeah. The debunking attempts are fascinating in their own right. Let's talk about those. Well, one of the most famous recent attempts came in 2017 from Antonio Paris, an astronomy professor. He proposed that the signal was caused by a massive, naturally occurring, hydrogen clouds surrounding two comets. Comets, Christiansen, and Gibbs, I believe. Right. Which we're supposedly moving through that region of space in 1977. But the original Big Year team dismantled that theory in the literature with just ruthless efficiency. They really did.

13:22They pointed out catastrophic flaws in the math. First, those specific comets weren't actually in the telescope's beam at the correct time. Kind of a big problem. Yeah. Second, the physics of commentary emission don't work. It's simply do not emit hydrogen signals anywhere near the massive strength required to produce a U on that printout. Right. And third, Paris' theory couldn't explain the feed horn problem. Comets move slowly across the sky. So if it was a comet, the signal would have been picked up by the first feed horn, and then a few minutes later, it would have been picked up by the second feed horn. But the wow signal only triggered one. Exactly. Even Jerry Im in himself, the man who wrote wow on the paper, he heavily doubted the extraterrestrial hypothesis for a time. What did he think it was? He proposed a terrestrial explanation suggesting it might have been a secret military earth signal that accidentally bounced off a piece of space debris and reflected perfectly back into the telescope. Oh, like space junk. Yeah. But, even later, retracted that skepticism. Further physics modeling proved that a piece of metallic space debris tumbling in low

14:25Earth orbit simply cannot reflect a terrestrial signal back into a fixed telescope to perfectly mimic a deep space source with a flawless 72 second rise and fall. Right. Because space junk moves far too fast and erratically. Exactly. It just doesn't work. But just recently, the debate was blown wide open again. In August 2024, the planetary habitability laboratory published a fascinating preprint drawing on data from the Aerosybo Observatory. Yes. And they actually proposed a totally new natural hypothesis to the lies on some incredibly complex astrophysics. This is currently one of the most compelling natural explanations we have. Break it down for us. So the researchers proposed that the wow signal was the result of a very rare transient astrophysical event known as stimulated emission, essentially a cosmic mazer. The theory suggests there was a cold, dark cloud of hydrogen gas sitting out in space. Suddenly, it was struck by massive stellar emissions from a highly energetic cosmic event behind it.

15:26Like what? That sounds intense. It is. This sudden immense injection of energy into the cold hydrogen cloud caused the atoms to synchronize their electron spin flips. So it triggered a chain reaction? Exactly. The energized cloud experienced a sudden, dramatic, highly focused surge in brightness at that exact 1420 megahertz frequency. It amplified the background radiation exponentially for a very brief period. So mechanically, it's like a cosmic neon sign floating invisibly in the dark. That's a great analogy. Right. It has all the gas inside, but no electricity. Then, a magnetar flare plugs it into a massive, momentary power surge. The hydrogen gas burns blindingly bright, beaming a highly focused laser of radio waves right as our telescope happens to be sweeping past that exact patch of sky. And then the energy dissipates, the cloud shorts out, and it goes dark forever. That perfectly captures the mechanics of a cosmic meser.

16:28It accounts for why the signal was so incredibly strong, why it was locked precisely at the hydrogen frequency, and most importantly, why we have never seen it again despite decades of searching. Because it was a one time event. Right. It wasn't an alien beacon left on. It was an astrophysical flash bulb going off in the dark. But regardless of whether it was a glowing cloud of synchronized hydrogen gas or an actual alien civilization, I mean, the psychological impact of the wild signal remains profound. Oh, absolutely. It totally changed our relationship with the cosmos. We desperately wanted to reach back into the dark. In 2012, for the 35th anniversary of the signal, the RECibo Observatory decided to officially talk back. Yes, they did. They gathered 10,000 promotional tweets using the hashtag chasing UFOs, which ironically was for a television show. And they beamed this digital stream of Twitter messages directly at nearby stars. The intention to respond was a milestone in human history, even if the execution was deeply, deeply flawed.

17:29Deeply flawed is an understatement. Yeah, the historical record of that event contains an incredible irony. According to the former director of the RECibo Observatory, the sheer power required to transmit that complex digital data caused the transmitter to literally overheat shortly into the very first transmission. Wait, they blew out their own equipment trying to send tweets to aliens? They did. And the data gets even worse. How could it be worse? Because of the equipment failure, the message was only sent in the direction of one of their pre-selected star targets. And none of the targets they chose were even in the possible region of Sagittarius where the wow signal actually originated. So to summarize our grand cosmic greeting, we took 10,000 tweets, pointed our massive radio dish at the entirely wrong part of the sky, yelled into the void, and promptly melted our own transmitter. But despite our bumbling, the signal's legacy endures. It showed up in the 1994 season premiere of the X-Files. It was a foundational plot point in the 2024 sci-fi series 3 body problem.

18:32It just has this absolute grip on our collective imagination. If we connect this to the bigger picture, the wow signal is the ultimate tantalizing data point in the history of science. It really is. Even if we never fully solve it, it served a vital transformative purpose. It forced humanity to drastically refine the mathematics and hardware of our radio astronomy techniques. It forced us to seriously debate our cosmic communication protocols, how we listen, and how we might responsibly respond. And as we saw with the 2024 Hydrogen Cloud Maser Theory, it is forcing us to look much closer at rare transient astrophysical phenomena that we might otherwise completely ignore. And for you listening, whether you walk away from this deep dive believing it was extra terrestrial intelligence saying hello, or a freak energized hydrogen cloud acting like a cosmic neon sign, the 72-second anomaly proves just how much of the universe's mechanics are still completely unknown to us. We really don't know much at all. We have only just opened our eyes to the radio universe.

19:33And I want to leave you with one final thought to mull over, building on what we discussed about that strict 72-second window in the rotation of the Earth. Oh, this is a good one. We spent decades analyzing the contents of the signal. What if it really was an extraterrestrial civilization out there? What if the message wasn't hidden in the radio wave itself? What if it was the delivery? Right. What if the message was in the exact timing of its arrival? What if an intelligence out there calculated the exact rotational speed of our planet? Didused exactly when our primitive, fixed radio telescopes would be sweeping past that precise patch of sky and sent a quick 72-second flash at the exact millisecond they knew we'd be looking. Just something to think about the next time you look up at the night sky. You're listening to a podcast right now, driving, working out, walking the dog. If you're into podcasts, chances are you have something to say too. With RSS.com, starting your own is free and easy. Upload an episode, and we distribute it to Apple podcasts, Spotify, Amazon music, and

20:38hundreds more. Track your listeners, see where they're from, and start earning from ads like this. And with just 10 listeners a month. If you've been thinking about starting a podcast, this is your sign. Start free at RSS.com.