Space & Astronomy

The famous 'Wow!' signal may finally have a definitive explanation

By T.K. Randall
August 22, 2024

Image: Wow! Signal
Credit: (PD) Big Ear Radio Observatory and North American AstroPhysical Observatory (NAAPO) Astronomers have been listening out for extraterrestrial signals for years, but one case - that of a strange signal picked up by a school telescope at Ohio State University over 40 years ago - has long remained one of the most tantalizing and perplexing examples ever recorded.

Originating in the globular cluster of M55 in the constellation Sagittarius, the peculiar signal lasted approximately 72 seconds. Astronomer Jerry Ehman, who was the first to examine the computer readout, famously wrote the word 'Wow!' on the page.

Although most experts have since dismissed the signal as naturally occurring, the specifics surrounding its source have remained a topic of debate for decades.

Now, though, the results of a new study aimed at finding similar signals in data previously collected by the now defunct Arecibo Observatory have indicated a potential solution to the mystery.

The researchers found various examples of similar, albeit weaker signals that they believe to be "easily identifiable as due to interstellar clouds of cold hydrogen (HI) in the galaxy."The Wow! signal, they argue, may have been a rare, souped up version of the same thing.

"We hypothesize that the Wow! Signal was caused by sudden brightening from stimulated emission of the hydrogen line due to a strong transient radiation source, such as a magnetar flare or a soft gamma repeater (SGR)," they wrote.

"These are very rare events that depend on special conditions and alignments, where these clouds might become much brighter for seconds to minutes."

This would also explain how the Ohio State University telescope was able to detect the Wow! signal, despite being unable to pick up similar signals under normal circumstances.

"Our hypothesis explains all observed properties of the Wow! Signal, proposes a new source of false positives in technosignature searches, and suggests that the Wow! Signal could be the first recorded event of an astronomical maser flare in the hydrogen line," the researchers concluded.

Source: IFL Science

Tags: Alien