The Wow! Signal: 72 Seconds That Stunned Astronomers

on 08/15/1977 a radio telescope in ohio picked up a signal from deep space that was 30 times louder than the background noise of the universe it lasted for exactly seventy two seconds and then it was gone we have never heard it again just yesterday in episode one twenty three we talked about the grandfather paradox a puzzle that seems impossible until you realize it's a trick question this is the opposite this is a question that seems simple but it might not have an answer so the signal gets recorded by this giant telescope called the big ear but nobody knows it's happened yet a few days later an astronomer named jerry eamon is going through reams of

computer printouts just pages of alphanumeric code representing cosmic static it's a thankless job but then he sees it a sequence of characters on the page six e q u j five in the system they were using low numbers meant background noise as you go up the number scale and then into letters the signal gets stronger u is about 30 times stronger than background noise so this sequence six e q u j five showed a signal that started low ramped up to an incredible peak and then ramped back down a perfect bell curve it was so clean so powerful and so textbook that eamon grabbed a red pen circled the sequence and wrote one word in

the margin wow okay so what was it the obvious thrilling answer is aliens seriously the signal was broadcast at fourteen twenty megahertz that frequency is called the hydrogen line and it's special it's the frequency at which neutral hydrogen the most common element in the universe naturally emits energy decades earlier two physicists at cornell philip morrison and giuseppe cocconi had proposed that any intelligent civilization wanting to send a cosmic hello would use this exact frequency it's the universe's most obvious channel a universal dial tone and the wow signal hit it dead on it looked exactly like the kind of intentional interstellar beacon seti was created to find but you have to be skeptical where have we

seen this before we see tantalizing patterns and noise all the time it's like seeing a face in the clouds or a clear trend in a chaotic stock market most of the time it's just our brains tricking us so scientists immediately started trying to knock the theory down could it be a natural phenomenon maybe a pulsar nope pulsars are like cosmic lighthouses they flash on a regular repeating schedule this was a one off what about a scintillating signal from a distant quasar basically a faraway object twinkling because of interstellar gas also unlikely those events are usually broad spectrum like a floodlight this was a laser beam a super narrowband signal confined to one tiny frequency slice the most recent theory involved comets suggesting a hydrogen cloud around a passing comet could have

done it but other astronomers ran the numbers and showed the two comets in question weren't even in the telescope's beam at the time every natural explanation they throw at it it just doesn't stick and here's the part that really gets me that seventy two second duration that wasn't random the big ear was a fixed telescope it used the earth's rotation to scan the sky any single point in space would drift through its field of view for you guessed it seventy two seconds the signal appeared grew to a peak as it crossed the center of the beam and then faded out precisely as it left the telescope's view it behaved exactly like a signal from a fixed point far far away in the constellation sagittarius someone or something was broadcasting and we just happened to be listening for that one minute and twelve seconds and then the earth turned and we missed the rest for over forty years we've pointed our best telescopes back at that same tiny patch of sky we found nothing absolute silence

it's like we overheard a single word from a conversation happening in another room and now we're just standing with our ear pressed to the door waiting for another sound the wow signal isn't a story about what we found it's a story about what we heard just once and the silence that followed is the real mystery it forces you to wonder what else we're missing what other whispers are flying past us every single second just because we're not pointing the right way at the right time