EARTH, Laniakea Supercluster—Imagine a 30-ton humpback whale gliding up to a small research boat and gently blowing a perfect bubble ring into the water. Is it just playing around, or is it trying to tell us something?

A new study from the SETI Institute and UC Davis suggests it could be the latter: these "underwater smoke rings" might be a deliberate attempt at communication, offering a fresh perspective on how intelligent life—whether aquatic or extraterrestrial—can connect across seemingly insurmountable gaps.

In a paper recently published in Marine Mammal Science, researchers detail 12 instances where 11 humpbacks created 39 bubble rings while humans watched nearby. The whales appeared calm, often still, and clearly undisturbed—behavior you wouldn't expect if they were feeding or feeling threatened. The implication is clear: they might have been saying “Hello.”

“Because of current limitations on technology, an important assumption of the search for extraterrestrial intelligence is that extraterrestrial intelligence and life will be interested in making contact and so target human receivers,” said Dr. Laurance Doyle of the SETI Institute when announcing the paper.

Dr. Fred Sharpe, co-lead author from UC Davis, emphasizes that this behavior goes beyond simple curiosity: “Humpback whales live in complex societies, are acoustically diverse, use bubble tools and assist other species being harassed by predators,” he said. “Now, akin to a candidate signal, we show they are blowing bubble rings in our direction in an apparent attempt to playfully interact, observe our response, and/or engage in some form of communication.”

The study places these bubble rings within the broader context of whale behavior. Humpbacks have long been known to create bubble nets to herd fish or use bubble curtains during mating displays—well-documented behaviors in marine science. But directing this behavior toward humans, across different populations in both the Atlantic and Pacific, hints at a potentially deeper purpose.

The Bubble Rings study is part of SETI’s larger WhaleSETI program—a bold initiative to explore non-human intelligence by studying the minds of Earth's whales. In 2023, WhaleSETI researchers reported a real-time "conversation" with a whale named Twain. By playing back recorded whale sounds through underwater speakers, they encouraged vocal responses over a 20-minute interactive session, raising hopes for meaningful, intelligent communication here on Earth.

Bubble rings, however, offer a different kind of communication: a visual vortex, intentionally shaped and directed, that could change how we define intelligence.

Historically, SETI has focused on technosignatures—radio waves, laser flashes—but approaches like WhaleSETI are expanding those methods. By studying how whales might intentionally reach out to another species, the hope is to develop "signal filters" that can recognize alien forms of contact that don't rely on electromagnetic signals alone.

Still, the researchers are careful not to jump to conclusions: bubble rings could be playful, exploratory—or simply reflexive. Dr. Jodi Frediani of UC Davis, co-lead author, points out, “The bubble rings seemed to be part of that interaction.” Drone footage from whale-watching operations showed bubble rings only when humans were present—a significant correlation.

As WhaleSETI continues its work, it brings us to an interesting point. While we've been scanning the skies for E.T., perhaps the first signs of cross-species intelligence that we find might come not from distant stars, but from our own oceans. If bubble rings are a whale's way of saying "hello," they might also be our first lessons in truly listening to voices as different as any we might find beyond our planet.