The Flash That Could Make Hydrogen Speak

Name: The Flash That Could Make Hydrogen Speak
Genre: Documentary

Researchers propose a cosmic chain reaction, but the precision of the surviving record cannot by itself identify what caused it.

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Transcript

The signal filled Big Ear's entire 72-second observation window—then vanished.
On August 15th, 1977, Ohio State's Big Ear surveyed the radio sky.
The data analyst manually reviewed computer output on line-printer paper. That reading is unusual.
It was strong, narrowband, and near the 8-inch (21-centimeter) hydrogen line.
The computer printout recorded six symbols: 6EQUJ5.
Volunteer astronomer Jerry Ehman circled the reading and wrote “Wow!” beside it.
The characters encoded changing channel energy, rather than a deliberate transmission.
The letter U peaked between 30 and 31 standard deviations above noise.
Six data points fit both a Gaussian curve and a squared sinc curve above .99.
But it appeared in only one of Big Ear's two beams.
Follow-up searches ran nearly 14 hours across multiple days and found nothing similar.
Researchers proposed a powerful transient radiation source brightening an interstellar hydrogen cloud.
A 2024 Arecibo study found weaker, similar signals from neutral-hydrogen clouds.
The proposed trigger was still unknown—possibly an object such as a magnetar.
That handwritten reaction gave the event its widely used name: the Wow! signal.

After the transient source and hydrogen clouds were proposed, a 2025 archival study still called the Wow! signal unexplained.

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