A journey into the greatest unsolved mystery in the search for extraterrestrial intelligence — the 1977 Wow! Signal detected by Ohio State's Big Ear telescope.
The greatest unsolved mystery in the search for extraterrestrial intelligence
What We'll Explore
01
A Signal from the Stars
02
What the Data Tells Us
03
The Hydrogen Fingerprint
04
Extraterrestrial or Not?
05
Why It Still Matters
02
THE DISCOVERY
August 15, 1977, just past midnight
Big Ear scans the Ohio sky
A signal arrives — loud and narrow
It lasts exactly 72 seconds
Sources: 1, 5
72 s
The signal rose, peaked, and faded — matching a celestial source passing through the beam
Sources: 1, 5
“
Wow!
Jerry R. Ehman, astronomer, on the computer printout
Sources: 1, 5
06
THE DATA
The Famous 6EQUJ5 Intensity Profile
Sources: 1, 4
1420 MHz — The Hydrogen Line
The universe's universal frequency
Hydrogen: the most abundant element
A quiet spot in the radio spectrum
Sources: 1, 4
~1420 MHz
Why This Signal Stood Out
<10 kHz
72 sec
1 of 50
Right at the hydrogen line
Extremely narrow bandwidth
Perfect celestial profile
Only one channel triggered
Sources: 1, 2, 4
10
THE MYSTERY
Two Competing Explanations
Extraterrestrial
Natural Source
Narrowband, hydrogen-line frequency, celestial profile — exactly what SETI predicted. But no repetition, no modulation, no encoding found.
Comet hypothesis proposed but widely rejected. Interstellar scintillation? Unknown astrophysical source? No natural explanation fully accounts for all features.
Sources: 3, 6
Never repeated. Still unexplained.
Dozens of follow-up observations. Zero confirmations.
Sources: 2, 3
The Search Continues
SETI keeps listening every night
New telescopes, new hope
The next 'Wow!' could be tomorrow
Sources: 2
References
[1] Wow! signal - Wikipedia — en.wikipedia.org
[2] The Wow Signal — seti.org
[3] Arecibo Wow! I: An Astrophysical Explanation for the Wow! Signal — arxiv.org
[4] The Wow! Signal — astronomyhouston.org
[5] Aug. 15, 1977: The Wow! Signal arrives — astronomy.com
[6] The Wow! Controversy and Decoding Alien Messages — smithsonianmag.com