Concept preview. Not indexed. Facts are checked against the sources listed on each page.
The Wow! signal: 72 seconds that never came back
The strongest candidate for an alien radio message ever recorded, and no one has been able to find it again.
| Recorded | 15 August 1977, Big Ear radio telescope, Ohio |
|---|---|
| Length | 72 seconds (the time the sky drifted across the telescope's view) |
| Frequency | close to 1420 MHz, the hydrogen line |
| Direction | in the constellation Sagittarius |
In human terms
- 72 seconds is a little over a minute. The whole case rests on one row of characters on a printout.
Measured: we know this
- A narrow, strong radio signal was recorded and flagged by a volunteer, who wrote "Wow!" on the printout.
- It has not been detected again in many follow-up searches.
Inferred: we think this
- The narrow frequency suggests something artificial, but natural sources have been proposed.
- A 2017 comet idea has been rejected by most astronomers.
Unknown: we do not know
- What produced it.
- Whether it was a one-off natural event, a glitch, or a transmission.
What would settle it
- A repeat detection from the same patch of sky.
- Records from other telescopes that were pointed there in 1977, if any exist.
Sources
Ohio State University Big Ear archive. NASA/SETI Institute summaries. Concept preview: verify details against the cited pages before launch.