The 72-Second Radio Signal From Deep Space That No One Can Explain

On August 15, 1977, astronomer Jerry Ehman was scanning the sky with the Big Ear radio telescope in Ohio when his equipment picked up a powerful 72-second radio signal. It came from deep space—unlike anything recorded before.

Ehman circled it and wrote one word in red ink: “Wow!” The name stuck.

For decades, scientists have debated the source. Some say it was a comet, others insist it might have been a message from extraterrestrials. Despite countless studies, no one has ever explained the Wow! signal.