Harvard astrophysicist Avi Loeb has ignited global intrigue by proposing that the interstellar object 3I/ATLAS, a colossal visitor roughly the size of Manhattan—spanning up to 11 kilometers in diameter—may be exhibiting signs of deliberate alien “maneuvering.” Discovered in July 2025 by the ATLAS telescope, this third confirmed interstellar comet has baffled astronomers with its anomalous behavior, including a bizarre “anti-tail” of gas and dust that points toward the Sun rather than away, defying the solar wind’s typical repulsive force. Loeb, renowned for his controversial theories on extraterrestrial artifacts like ‘Oumuamua, argues this sunward jet isn’t an optical illusion but evidence of controlled propulsion, potentially an Oberth maneuver where the object harnesses the Sun’s gravity for efficient acceleration. As 3I/ATLAS hurtles through our solar system at speeds exceeding 130,000 mph, its immense mass—a million times that of ‘Oumuamua—and unusual trajectory past Mars, Venus, and Jupiter fuel speculation that this isn’t a passive icy wanderer but a engineered probe scouting our cosmic neighborhood.

Just days before slipping behind the Sun for its solar conjunction on October 21, 2025, 3I/ATLAS captivated observers with strange pulsating patterns in its emissions, detected by telescopes like Hubble and James Web These rhythmic bursts of gas, including rare cyanide and atomic nickel vapor, align with solar heating but exhibit an unprecedented geometry: elongated glows ten times longer than wide, forming jet-like structures unlike any cataloged comet. Loeb highlights the object’s emission of a nickel-based metal alloy devoid of iron—a composition eerily reminiscent of human industrial alloys—alongside extreme negative polarization never seen in natural comets. While NASA insists these are quirks of an ancient, 7- to 14-billion-year-old relic from the Milky Way’s thick disk, the pulsating cadence, timed suspiciously with its perihelion approach on October 29, evokes images of artificial signaling or course corrections. This flurry of oddities, observed mere days ago, has astronomers scrambling for data before the object’s temporary invisibility, wondering if these pulses are the heartbeat of alien ingenuity.

Though 3I/ATLAS will “come to Earth soon” in relative cosmic terms—reaching its closest approach on December 19, 2025, at a safe 1.8 astronomical units (about 170 million miles)—its passage promises a pivotal moment for humanity’s gaze skyward. Emerging from solar occultation in late November, the comet will offer a final window for scrutiny by missions like ESA’s Juice, which will pass within 64 million kilometers on November 4. Loeb warns that this hidden phase behind the Sun could be an opportune veil for a “black swan” event, like deploying mini-probes toward Earth, though he concedes the likelihood of natural origins remains high. Far from posing a collision risk—NASA confirms it stays well beyond Mars’ orbit—this Manhattan-scale enigma challenges our assumptions about interstellar travelers, blending awe with unease as it slingshots away, leaving us to ponder if we’ve just hosted an unwitting cosmic envoy.