Harvard astrophysicist Avi Loeb reports that the interstellar visitor 3I/ATLAS produced multiple jets after its Oct. 29 close pass by the Sun. He described at least seven jets, some directed sunward and extending over a million kilometers through the solar wind. Loeb says the object is losing significant mass and may have fragmented into roughly a dozen pieces, and he estimates that a natural-comet explanation would require roughly 5 billion tons of ejected material. He also noted an alternative explanation — thrusters — could produce similar jets with much less mass; forthcoming NASA HiRISE images may help resolve the question.
Avi Loeb: Interstellar Object 3I/ATLAS Sprays Multiple Jets After Oct. 29 Solar Flyby
Harvard astrophysicist Avi Loeb reports that the interstellar visitor 3I/ATLAS produced multiple jets after its Oct. 29 close pass by the Sun. He described at least seven jets, some directed sunward and extending over a million kilometers through the solar wind. Loeb says the object is losing significant mass and may have fragmented into roughly a dozen pieces, and he estimates that a natural-comet explanation would require roughly 5 billion tons of ejected material. He also noted an alternative explanation — thrusters — could produce similar jets with much less mass; forthcoming NASA HiRISE images may help resolve the question.
04:43 PM, 11/11/2025Science
Avi Loeb: 3I/ATLAS Shows Multiple Jets After Passing Close to the Sun
Harvard astrophysicist Avi Loeb, who has been monitoring the interstellar visitor 3I/ATLAS, reports that the object produced several distinct jets after its close approach to the Sun on October 29. Loeb said the jets appear to extend more than a million kilometers through the solar wind and that at least seven separate outflows were observed.
"What we see are seven jets coming out of these objects, more than seven actually, after it passed close to the sun on October 29," Loeb told NewsNation's Elizabeth Vargason. "Some of these jets are pointed towards the sun, and they penetrate over a million kilometers through the solar wind."
Loeb says 3I/ATLAS has been losing a significant amount of mass and that rapid mass loss could indicate the object has fragmented — possibly into roughly a dozen smaller pieces. The object is expected to make its closest approach to Earth in December.
To explain the observed jet properties, Loeb compared two scenarios. In a conventional, natural-comet model — where jets are produced by pockets of ice sublimating — the measured jet speeds and the known density and speed of the solar wind would imply the outflows carry on the order of 5 billion tons of material to penetrate as observed. By contrast, if the jets are produced by engineered thrusters, those systems can expel gas at much higher speeds, meaning far less mass would be required to create similar-looking jets.
Loeb emphasized that these interpretations are tentative and that upcoming data could be decisive. He noted that images taken by NASA's HiRISE camera aboard the Mars Reconnaissance Orbiter around the time of the U.S. federal government shutdown may shed light on the object's structure; those images have not yet been released.
What the name means
The designation 3I/ATLAS indicates this is the third interstellar object confirmed to enter our solar system (3I) and that it was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS).
Note: The statements above reflect Avi Loeb's analysis and interpretation of the observations. His views represent a scientific perspective under active discussion and investigation.