Harvard Astronomer Reports “Major Anomaly” in Mass of Interstellar Object 3I/Atlas
CAMBRIDGE, MA – An interstellar object currently traversing our solar system, designated 3I/Atlas, is exhibiting characteristics that defy conventional understanding, according to a new analysis by Harvard astronomer Avi loeb. Preliminary measurements suggest the object possesses a mass exceeding 33 billion tons – considerably larger than previously estimated for similar interstellar visitors.
loeb’s research, posted on Harvard’s website, indicates 3I/Atlas coudl be substantially more massive than other known interstellar objects like ‘Oumuamua and Comet 2I/Borisov. This discrepancy presents a “major anomaly,” challenging existing models of how these objects form and travel through space. The findings stem from observations of the object’s non-gravitational acceleration, a phenomenon influenced by factors like outgassing or, possibly, an unusual composition.
Interstellar objects – those originating outside our solar system – are rare opportunities to study materials from other star systems. The first confirmed interstellar visitor,’Oumuamua,discovered in 2017,sparked intense debate about its origin and nature. Comet 2I/Borisov, discovered in 2019, provided a more conventional cometary profile. 3I/atlas, discovered in 2023, initially appeared as a comet, but its behavior has proven more complex.
Astronomers will have a chance to gather more data as 3I/Atlas approaches its closest point to the Sun. Observations are planned using the HiRISE camera onboard the Mars Reconnaissance Orbiter on October 3,2025. however, the object will be positioned on the opposite side of the Sun during its closest approach, temporarily obscuring it from view before reappearing in December.
The recent commissioning of the Vera C.Rubin Observatory promises to accelerate the finding and characterization of interstellar objects. In just 10 hours of operation, the observatory identified 2,104 new asteroids, a rate far exceeding previous discovery rates of approximately 20,000 per year. This increased observational capability offers the potential to unlock further insights into 3I/Atlas and future interstellar visitors.
https://lweb.cfa.harvard.edu/~loeb/CLV.pdf
