Interstellar Object 3I/ATLAS Defies Comet Norms as Mystery Grows

The interstellar object 3I/ATLAS is challenging established theories about comets, particularly with its recent observations. New images captured on November 5 at the R. Naves Observatory in Spain reveal that this object, roughly the size of Manhattan, lacks a tail—an expected feature of comets as they approach the Sun. This absence has led some scientists to question whether 3I/ATLAS is indeed a naturally occurring comet.

Astrophysicists have noted that a typical comet, when heated by solar radiation, should produce a substantial “coma” of gas and dust, resulting in a tail that can account for up to 13% of its mass. According to Avi Loeb, an astrophysicist from Harvard University, if 3I/ATLAS continues to show no tail, it suggests a different composition or origin. In comments to the New York Post, he stated, “It is likely not a naturally occurring comet.” Loeb further explained that the object exhibits non-gravitational acceleration, which would typically require significant evaporation of its mass, but preliminary images post-perihelion show no evidence of this phenomenon.

Unusual Characteristics of 3I/ATLAS

3I/ATLAS has displayed several anomalies since its discovery. Notably, it brightened by a factor of five after perihelion and took on an unusual green hue. Additionally, it features an “anti-tail” that points toward the Sun, contrary to the expected behavior of a comet. This hyperbolic trajectory indicates that the object has originated from outside our Solar System.

Loeb has compared the current images of 3I/ATLAS to those of the solar system’s comet Lemmon, which displays a characteristic tail pointing away from the Sun. The stark difference between these two objects raises further questions about the nature of 3I/ATLAS.

Future Observations and Implications

Looking ahead, the most detailed images of 3I/ATLAS are anticipated to come from NASA’s Mars Orbiter, specifically its HiRISE camera. However, the release of these images has been delayed due to the ongoing government shutdown. As reported by the New York Post, 3I/ATLAS is currently on a trajectory that will bring it near Jupiter on March 16, 2026. During this close approach, two orbiters from NASA and the European Space Agency will be positioned to observe the object closely.

3I/ATLAS first entered our solar system on June 14, 2025, and its peculiar characteristics continue to spark interest and debate among scientists. The investigation into its origins and behavior not only challenges existing comet theories but may also contribute to a deeper understanding of interstellar objects and their potential implications for our solar system.