The Strange Space Signal NASA Can't Solve

"August 15, 1977"

It was a routine day at Ohio Wesleyan University, but on this night, something was about to happen that would remain a mystery to humans for years to come.

At the university, the Big Ear radio telescope, with its 30-meter-wide reflector, detected a powerful radio signal at 10:16 PM. This signal passed through the telescope to an IBM 1130 computer, and from there, it was automatically converted and sent to a printer.

Except for the sound of the printer in the control room, the night was silent. The signal that was printed got buried among other printouts, and no one realized at the time that the Big Ear telescope had just received a signal from the Sagittarius constellation — potentially from an alien source.

A few days later, a technician was reviewing the printouts when astronomer Jerry Ehman spotted the signal. He highlighted it in red pen and wrote “Wow!” beside it. Since then, the signal is famously known as the "Wow! Signal."

Why Was the Signal So Special?

For the past 47 years, astronomers have debated whether the signal — received from the Sagittarius constellation — was a message from intelligent extraterrestrials or just a cosmic coincidence.

In 1959, physicists Philip Morrison and Giuseppe Cocconi from Cornell University published a paper suggesting that if there were any intelligent alien civilizations in the universe, they would most likely communicate at a frequency of 1420 MHz. This frequency is naturally emitted by hydrogen, the most abundant element in the universe, making it a likely “universal reference” for communication.

Following this idea, in 1973, Ohio State University dedicated the Big Ear telescope to a mission called SETI (Search for Extraterrestrial Intelligence). Its goal: to detect intelligent signals coming from outside Earth.

The Night of the Signal

On the night of August 15, 1977, at 10:16 PM, the telescope received a unique and powerful signal. It lasted 72 seconds and was recorded as:

6EQUJ5

This string isn't a code or message in letters and numbers — it represents the intensity of the signal over time.

Each character in the signal represents 12 seconds. So:

• 6 → First 12 seconds
• E (value = 14)
• Q (value = 26)
• U (value = 30)
• J (value = 20)
• 5 → Last 12 seconds

This means the signal grew in intensity and then faded — a pattern consistent with a deliberately transmitted signal, not a natural or random one.

Also, it was detected only at 1420 MHz — the exact frequency linked to hydrogen, adding to the belief that it might have been a deliberate alien transmission.

But Why Was It Never Heard Again?

Many have questioned:

Could it have been a random signal from an asteroid, a planet, or a cosmic event?

Possibly. But several facts argue against that:

• Cosmic events don’t produce such structured signals.
• The Wow! Signal was never repeated, which is strange for a natural phenomenon.
• It only came through one feed horn of the telescope, not both — and due to the telescope’s design, it’s impossible to determine the exact source direction.

The region it came from lies near the globular cluster M55 and Tau Sagittarius, but the precise coordinates remain unknown.

Theories & Failed Replications

Many attempts have been made to detect the signal again:

• In 1995, Paul Shuch used the Greek Bank Observatory.
• In 1999, Gray and Ellingson used the Mount Pleasant Radio Observatory.
• In 2017, Antonio Paris suggested the signal came from hydrogen clouds associated with comets 266P/Christensen and 335P/Gibbs.

But none of these theories have been conclusively proven, and no telescope has picked up the signal again.

Could It Be Earth-Origin?

Some theorized it was a signal from Earth that reflected off a space object (like debris or an asteroid). But this was ruled out because:

• Earth-based transmissions are not permitted at 1420 MHz (reserved for astronomy).
• A reflected Earth signal wouldn't be strong enough to reach the telescope with such intensity.

So, Was It Aliens?

We still don’t know.

It may have been a one-time message from an intelligent civilization — or it may remain one of the biggest unsolved mysteries in astronomy.

As of today — 47 years later — the Wow! Signal has never been heard again.