This post concerns my weird interest in astronomy.
When something truly startling happens, people say: “OMG!” or the dreaded, “Awesome!” But when Jerry Ehman sat at his kitchen table on Aug. 15, 1977, and saw six numbers and letters on the computer printout in front of him — six symbols that have become one of the grandest riddles in modern science — he chose the simplest expression of all. He took a red pen, circled the letters and then wrote:”WOW!”
Eighteen years earlier, two Cornell physicists, Philip Morrison and Giuseppe Cocconi, had tried to imagine how an intelligent alien civilization might try to signal Earth. We should look, they said, for a radio transmission. Radio waves are cheap to produce, don’t require much energy and travel vast distances across space.
Cocconi and Morrison guessed that the aliens would choose a frequency that would mean something to creatures who know math and chemistry. Hydrogen is the most common element in the universe. Zap a hydrogen atom and it will resonate at a particular rate: 1420 megahertz (MHz). So look, they said, for a signal coming in at 1420 MHz. And look for something loud, something that would catch our attention.
And what can we say, it came as they said it would.
What Jerry saw was a radio signal very, very close to 1420 MHz (it was 1420.4556, just a smidge from where it was expected). It lasted 2 to 2 1/2 minutes. It was loud. And the transmission had the shape that Cocconi and Morrison had predicted. If you look at this printout, you will see this sequence of letters and numbers: 6EQUJ5.
Now the letter are a code for the intensity and higher the letter higher the intensity.
That’s why when Jerry saw this letter U on his printout (U is the 21st letter of the alphabet) he knew something was up.
“I had never seen any signal that strong before,” Jerry says. “U,” in a logarithmic way, means about 30 times louder than the ordinary noise of deep space. That’s kind of a “Hello!” level. And that explains Jerry’s reaction.
“That’s the nice thing about the word ‘wow.’ I was, uh … I was astonished,” he says.
After all these years, SETI has been yet been unable to find a recurrence of the signal, though they were able to determine that the signal seemed to have originate from the Sagittarius constellation.Why only one signal? If an alien intelligence is trying to send a message somewhere, wouldn’t it make sense to send the message a few times? The signal landed once on Aug. 15, 1977. It never repeated.
And yet, the “Wow!” signal is the only reliably recorded sound apparently received from deep space that has the quality of an intentional signal. Jerry Ehman has never claimed he’d heard from E.T. Where the signal came from is still an open question for him. All Jerry Ehman will say is that having eliminated (as best he can, two galaxies colliding too has been eliminated) every other explanation, a message from E.T. is one possibility he can’t dismiss.
The question “Are we alone in the universe ?” (what I think is the most profound one) could have been possible answered by the “WOW!” signal and who knows it still may answer it.
Michael Brook’s account of the “Wow!” signal is probably the best I’ve ever read. It can be found in chapter seven of his book “13 Things That Don’t Make Sense,” published in 2008.