Study Attributes 3I/ATLAS's Non-Gravitational Acceleration to Conventional Outgassing
Recent research suggests that the interstellar comet 3I/ATLAS's unexpected acceleration is due to standard volatile outgassing, eliminating the need for exotic explanations.
The interstellar comet 3I/ATLAS, discovered on July 1, 2025, has exhibited non-gravitational acceleration during its journey through the Solar System. This phenomenon, where an object's velocity changes due to forces other than gravity, is commonly observed in comets as they release gases when heated by the Sun.
In a recent preprint paper, Florian Neukart of the Leiden Institute of Advanced Computer Science analyzed this acceleration using thermophysical and Monte Carlo models. The study concluded that the observed changes in 3I/ATLAS's velocity can be fully explained by the outgassing of conventional volatiles, primarily carbon monoxide (CO) and carbon dioxide (CO₂), under realistic surface and rotational conditions. Neukart stated, "Our results show that a conventional volatile-driven mechanism reproduces both the magnitude and the direction of the acceleration for realistic active fractions and jet collimation."
This finding challenges previous speculations that the comet's acceleration might be due to exotic compositions or even artificial origins. The study emphasizes that the acceleration can be attributed to natural processes, eliminating the need for non-physical or exotic explanations. Neukart added, "These results eliminate the need for non-physical or exotic explanations and define thermophysical limits for natural acceleration mechanisms in interstellar comets."
Further observations are planned to monitor 3I/ATLAS as it continues its trajectory through the Solar System. These studies aim to provide more insights into the behavior of interstellar objects and the mechanisms driving their motion.