Interstellar Object’s Jets Challenge Existing Comet Theory
CAMBRIDGE, MA – November 2025 - New analysis of the 12th observed anomaly of the interstellar object 3I/ATLAS reveals its two prominent jets are not smeared by rotation as predicted by standard comet models, bolstering the hypothesis that the object possesses a unique, potentially artificial, internal structure. The findings, published by Avi Loeb and his team at the Galileo Project, represent a significant challenge to conventional understanding of cometary behaviour and further fuel debate surrounding the object’s origins.
The implications of this discovery extend beyond the realm of astronomy.3I/ATLAS, discovered in 2023, is only the third interstellar object detected passing through our solar system. Its unusual characteristics – including its unexpectedly high velocity and the observed anomalies in its jet activity - have prompted scientists to reconsider the possibility that some such objects might not be naturally occurring. Understanding the composition and behavior of these interstellar visitors is crucial for assessing potential risks and opportunities, and for refining our understanding of planetary system formation and the prevalence of life beyond Earth.
Avi Loeb, head of the Galileo Project and founding director of Harvard University’s Black Hole Initiative, explains that the observed jets, emanating from 3I/ATLAS, maintain a consistent orientation despite the object’s rotation. “standard comets exhibit jets that are smeared out due to their rotation, creating a more diffuse pattern,” Loeb stated. “The fact that the jets in 3I/ATLAS remain focused suggests an internal structure that resists this smearing effect.”
The Galileo Project team utilized observations from the Green Bank Telescope to analyze the object’s radio emissions, allowing them to pinpoint the origin and direction of the jets. This detailed analysis revealed that the jets are not randomly oriented, but rather aligned in a manner inconsistent with a typical rotating comet nucleus.
Loeb is the bestselling author of Extraterrestrial: The First Sign of Clever Life Beyond Earth (2021) and Interstellar (2024), and a co-author of the textbook Life in the Cosmos (2021). He previously served on the President’s Council of Advisors on Science and Technology and chaired the Board on Physics and Astronomy of the National Academies. The Galileo Project continues to monitor 3I/ATLAS as it moves further from the sun, seeking additional data to unravel the mystery surrounding its unusual characteristics. Further research will focus on determining the object’s composition and internal structure, potentially offering definitive clues about its origin and nature.
(Image Credit: Chris Michel, National Academy of Sciences, 2023)
