Does 3I/ATLAS’ ‘heartbeat’ prove alien origins?: comet expert Avi Loeb

Is 3I/ATLAS following its heart?

Harvard scientist Avi Loeb believes that 3I/ATLAS boasts a “heartbeat”-like pulse that could provide evidence of its artificial origins — potentially even pointing to the inner-workings of a spaceship.

“The pulses could be periodic thrusts for orbit corrections or some other internal cycle within the spacecraft,” the astrophysicist told the Post.

In a recent blog on Medium, titled “are the Jets from 3I/ATLAS pulsed like a heartbeat?” Loeb wrote that following its July discovery, our interstellar visitor’s light blinks in a regular cycle that repeats every 16.16 hours like an interstellar lighthouse. The so-called cosmic cadence was observed in a study published over the summer in the journal “Astronomy and Physics.”

Loeb wrote that this celestial drumbeat should have been apparent in a series of “well-calibrated” photos of ATLAS over several days but none were “systematically studied in the published literature.”

Analysts claimed that the “heartbeat” originated from the rotation of the nucleus, but Loeb told the Post that this was improbably as “less than ten percent of the light comes” from the center.

Rather, based based on the Hubble Space Telescope image snapped on July 21, 2025, the lion’s share of the glow emanates from the coma — the halo of gas and dust that forms around the solid nucleus when the comet approaches the Sun.

“Therefore the periodic modulation of its light must originate from its puffs of gas and dust that scatter sunlight around it,” Loeb told the Post. “The puffs are periodic, like the blood stream of a heartbeat.”

The researcher reiterated in the the blog post that ATLAS has multiple jets — which he previously speculated could be a set of advanced artificial thrusters. He noted that if the entity releases material in regular intervals, then the coma would brighten and dim in a corresponding rhythm as it reflects sunlight like, well, intergalactic Morse code.

If ATLAS were a natural comet, Loeb wrote, this phenomenon could “can arise from a sunward jet (anti-tail)” that pulses only “when a large pocket of ice on one side of the nucleus is facing the sun.”

“The coma will get pumped up every time the ice pocket is facing the sun,” he explained.

If ATLAS is artificial, on the other hand, the pulsing jet’s position in relation to our solar star could be “arbitrary” as another potentially internal mechanism is at work.

Loeb claimed that footage showing the brightening of the jets around 3I/ATLAS over several days could shed light on whether the jets are natural or technological based on if the blinking tails are pointed toward the sun. One could think of it like a celestial cardiogram.

Why would the jet be pulsing if it were of extraterrestrial provenance? Loeb speculated that ATLAS could be executing thrusts to adjust the object’s trajectory or some other function.

Last week week, Loeb posited that the comet’s bizarre trajectory toward Jupiter — which it will reach in March — suggested that it seed the gas planet with “satellites” to gather intel for an “extraterrestrial civilization.”

He posited that it may have even used rocket boosters to change course during its monthlong passage near perihelion — the object’s closest approach to the sun — to ensure it was within proper range.

“It might have fine-tuned its trajectory with the help of [artificial] thrusters,” he said.

NASA’s official position, which the agency reiterated during its anticipated photo release in Maryland two weeks back, remains that 3I/ATLAS is a comet.