Astronomers Revisit the Mysterious Wow! Sign—and Discover a Huge Shock

Almost 50 years in the past, astronomers looking out the cosmos for proof of clever extraterrestrial life detected a robust radio sign emanating from deep house. As we speak, scientists nonetheless aren’t positive the place—or what—the Wow! Sign got here from. It stays some of the perplexing phenomena within the historical past of radio astronomy.

A brand new examine has introduced scientists nearer than ever to fixing that thriller. Researchers from the Arecibo Wow! (AWOW) undertaking on the Arecibo Observatory in Puerto Rico just lately re-analyzed the sign and many years of unpublished observations that adopted its detection. The findings, submitted to The Astrophysical Journal for peer overview on August 14 and presently obtainable on the preprint server arXiv, considerably revise the Wow! Sign’s parameters and supply probably the most exact evaluation up to now, the researchers say.

A decades-long thriller

When the Huge Ear Observatory in Ohio first detected the Wow! Sign on August 15, 1977, SETI (Seek for Extraterrestrial Intelligence) astronomer Jerry R. Ehman was so dumbfounded by its depth that he circled it in purple and wrote “Wow!” beside it, therefore the title. The sign instantly stood out to Ehman and his colleagues as a possible candidate for extraterrestrial radio transmission, however through the years, mounting evidence has pointed to natural explanations.

In recent times, researchers led by Abel Méndez—lead creator of the brand new examine and director of the Planetary Habitability Laboratory on the College of Puerto Rico—have contributed considerably to that proof by way of the AWOW undertaking. In August 2024, Méndez and his colleagues printed findings that recommend the Wow! Sign stemmed from the sudden brightening of a cold hydrogen cloud attributable to a transient supply of radiation corresponding to a magnetar. These neutron stars have magnetic fields sturdy sufficient to excite the atoms in hydrogen clouds and elicit a burst of brightness.

Re-evaluating the Wow! Sign

Now, Méndez’s crew has meticulously retrieved and analyzed many years of archival SETI knowledge to re-evaluate the Wow! Sign’s properties and assess that speculation. Accessing trendy knowledge evaluation instruments and up to date observations was a “recreation changer” for this examine, Méndez instructed Gizmodo. Such developments allowed his crew to calculate extra exact measurements for the Wow! Sign’s location of origin, depth, and frequency. “In numbers, [these revisions] look small, however they aren’t small,” he stated.

The researchers’ calculation for the sign’s depth—or flux density—was 4 instances better than earlier estimates, however the revised frequency was most shocking to Méndez. He and his colleagues discovered it to be 1420.726 MHz—a lot increased than they anticipated. The findings recommend the Wow! Sign got here from a supply inside our galaxy, transferring quicker than scientists beforehand thought.

Thriller solved? Not but

This provides weight to the researchers’ chilly hydrogen cloud speculation and to the broader concept that this sign arose from a pure astrophysical phenomenon reasonably than terrestrial radio interference. That stated, the case isn’t closed—but.

“We’re assured—and shocked—that we’re getting nearer,” Méndez stated. Over the subsequent two years, he and his colleagues will proceed publishing new findings from the archival SETI knowledge, hopefully progressing towards an answer to this decades-long thriller.