If you read my previous post (and if you haven't, I suggest you do so. I'll wait. No really. Do it.) then you know that I have become a member of SETI@Home. As synchronicity would have it, I did so unaware that today is the anniversary of the "Wow!" signal. No really, I was unaware. Trust me, I'm not that profound.
What exactly is the "Wow!" signal? Glad you asked.
On August 15th, 1977, SETI astronomer Dr. Jerry Ehman was going through data received by a radio telescope at Ohio State University. What he found that day was a narrow band radio signal that was over 30 times louder than the normal noise of deep space. The signal lasted a full 72 seconds. Ehman circled it and wrote the word "wow!" in the margins thusly...
The vertical series of alpha-numerical values has been called the "Wow!" signal ever since.
Point of origin was estimated to be somewhere in the Sagittari star cluster. Efforts were immediately launched to find the signal again. SETI radio telescopes turned their dishes towards Sagittari...
And have been looking ever since. Though the strength of the radio signal is consistent with what an alien transmission is guessed to look like, the signal should have repeated itself at least at some point during the past 33 years. This casts considerable doubt on the captured signal being of extraterrestrial origin. So then what was it?
One school of thought suggests that was a regular interstellar radio burst, amplified through an effect similar to atmospheric twinkling. Dr. Ehman himself once suggested that the signal could have originated on Earth and then bounced back off of a bit of space debris. He eventually stepped away from that theory. You see, the signal was 1420 MHz, a protected bandwidth upon which Earth transmissions are prohibited. The more that is learned about radio astronomy, the more anomalous the "Wow!" signal becomes.
A few have suggested that it was a transmission caught from a passing alien spacecraft. Who knows? But the bottom line is that the no conclusive explanation has ever been found for the signal. "Wow!" may be destined to forever remain a mystery of astronomy.
So if my little SETI@Home volunteerism turns up anything like "Wow!", you'll read it here first on Strange Horizons.
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