(Photo: NASA/Goddard/SwRI/JHU-APL)
When theoretical physicist Michio Kaku went on Newsmax in late October and told viewers to "watch for it," he framed a clear test for the interstellar object 3I/ATLAS: if it received an "extra burst of energy" at perihelion that gravity could not explain, then "we are being visited". At the time, the line sounded more like a television soundbite than a research agenda. A month later, the trajectory data now being debated by astronomers match the scenario he described.
On Oct. 30, as 3I/ATLAS swung through its closest approach to the Sun, NASA's JPL Horizons system registered a non-gravitational acceleration term of 1.6 x 10^{-6} au/day^2. The value corresponds to an additional push on the object of roughly 0.05 millimetres per second per day - minute on human scales but large enough over weeks to produce a measurable deviation from a purely gravitational path. By Nov. 24, updated modelling reduced the term to 4 x 10^{-7} au/day^2, but the presence of an extra force remained in the solution.
Under standard cometary physics, such non-gravitational accelerations are attributed to outgassing: as sun-heated ices vaporise, the recoil of escaping gas acts like natural thrusters. What troubles some analysts is not that 3I/ATLAS shows this effect, but that the magnitude, timing and apparent radial dependence of the acceleration do not sit neatly inside conventional models. JPL's trajectory solution has already been revised several times to account for the changing estimates.
Key reported figures for 3I/ATLAS include:
- Non-gravitational term on Oct. 30: 1.6 x 10^{-6} au/day^2
- Revised value by Nov. 24: 4 x 10^{-7} au/day^2
- Effective push: ≈ 0.05 millimetres per second per day (initial solution)
Kaku's own tone has since softened, with the original threshold - that "extra energy equals visitation" - no longer foregrounded in his public remarks. But as one prominent theorist stepped back from the implications, another moved in with a detailed set of calculations.
Avi Loeb of Harvard, known for his work on interstellar object 'Oumuamua, has published analyses arguing that 3I/ATLAS may display behaviours consistent with "intelligent control", "engineered structure", or "deliberate orientation". Loeb's work, circulated in academic-style write-ups rather than television segments, focuses on mismatches between the JPL Horizons model and the observed brightness and motion of the object.
According to this line of analysis, the JPL solution underestimates the brightness surge of 3I/ATLAS near perihelion and relies on radial acceleration assumptions that may not fit the observed luminosity curve. Adjusting that radial dependence could, in principle, change projected geometry near Jupiter's orbit and reopen questions about how - and why - the object is moving as it does. Loeb has previously suggested that some interstellar objects might be "light-sails", thin structures or devices propelled by non-gravitational means; in 3I/ATLAS he sees echoes of earlier anomalies.
Beyond the acceleration term, advocates of a technological hypothesis point to a wider list of peculiarities. The object is described as showing rotational spin waves propagating through its coma, a repeating geometric envelope that appears in independent images taken weeks apart, and a nickel-dominant emission pattern unlike that seen in typical comets. The reported nickel-to-iron (NiI/FeI) ratio is unusually high, and the chemistry has been linked to low-temperature sublimation of complex organic-metal compounds such as metal carbonyls - a composition that standard comet formation scenarios do not readily predict.
Another claimed anomaly is a sunward-facing anti-tail, which sits uneasily with classical dust-dynamics models. Taken together, proponents argue, the "combination of features - internal coherence, external structure, coordinated wavefronts and non-gravitational acceleration - are simply not the behaviours of a chaotic snowball."
The narrative now emerging places Kaku's early warning and Loeb's modelling work on a converging track. One scientist set a public threshold - "extra burst of energy" at perihelion - and another has begun to catalogue how that "extra energy" might be consistent with scenarios of "intelligent control". Their methods differ, but both are now associated with the same core question about 3I/ATLAS.
Neither, however, has declared proof of an artificial origin. As the article notes, Loeb uses formulations such as "technological origin cannot be ruled out" and "consistent with artificial mechanisms", while Kaku has largely backed away from his more categorical October line that "we are being visited". The gap between the language of scientific caution and the implications some readers draw from it has widened as more data have come in.
The broader research community has reacted in a characteristically incremental way: updating fits, revising non-gravitational terms, and debating radial profiles for mass loss rather than embracing a definitive explanation. USA Herald has framed the situation by saying: Prof. Michio Kaku's Warning and Avi Loeb's Hypothesis Now Converge as 3I/ATLAS Displays Behaviors Consistent With Intelligent Control, a headline that underscores how far public discussion has moved beyond standard comet talk.
Attention is now turning to the next key observation window, centred on Dec. 19, when ground-based and space-based observatories expect to secure improved imaging and astrometric data. Analysts watching for further anomalies are focused on a short list of indicators: whether non-gravitational acceleration persists or changes character, whether any structural geometry emerges in higher-resolution imaging, and whether the reported anti-tail and wavefront behaviour remain aligned with earlier claims.
