Wow! Signal: Mysterious Radio Pulse from Deep Space
Volunteer astronomer Jerry Ehman was reviewing printouts from Ohio State's Big Ear radio telescope on August 15, 1977, when he spotted a signal 30 times stronger than the background noise coming from the constellation Sagittarius. He circled the reading and wrote "Wow!" in the margin. The signal lasted exactly 72 seconds, the maximum duration a stationary telescope could observe a fixed point in the sky. It matched the expected profile of an extraterrestrial transmission: a narrow-band signal at the hydrogen line frequency of 1420 MHz. Despite hundreds of subsequent attempts to detect the signal again using progressively more sensitive equipment, it has never recurred. The Wow! signal remains the strongest candidate for an alien transmission ever recorded.
August 15, 1977
49 years ago
Key Figures & Places
Ohio State University
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The Big Ear
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radio telescope
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Wow! signal
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SETI
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Ohio State University Radio Observatory
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Radio telescope
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Ohio State University
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Search for extraterrestrial intelligence
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Wow! signal
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Ohio
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United States
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Jerry Ehman
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