In November 2025, something extraordinary happened at perihelion that shook the very foundations of our understanding of interstellar objects.
An object passing close to the sun should behave according to the laws of gravity.
Yet, in the case of 3I/ATLAS, those laws didn’t add up.
The object accelerated beyond what gravitational models predicted, and this anomaly is about to change everything we thought we knew about the cosmos.
Here’s why the latest data has profound implications—and it could rewrite the entire narrative of 3I/ATLAS.
The Unpredictable Acceleration of 3I/ATLAS
On November 29, 2025, 3I/ATLAS reached its closest approach to the sun, coming within 0.7 astronomical units (AU) of the solar center.
According to our models, we expected a certain velocity increase due to solar gravity.
However, when we measured the actual velocity, something was off—3I/ATLAS was moving significantly faster than predicted.
The acceleration was approximately 300 m/s greater than what gravitational models suggested.
While 300 m/s may seem like a small number, in orbital mechanics, it’s enormous.
This is enough to change the trajectory of an object, and in this case, it meant 3I/ATLAS was deliberately altering its path.
This acceleration wasn’t random.
It was sustained, directional, and perfectly timed.
When we consider the timing, it’s even more troubling—this acceleration happened at perihelion, when the object was closest to the sun, closest to maximum observation opportunity, and closest to Earth for potential communication.
This raises the obvious question: What caused this unexpected behavior?
The Standard Explanation: Outgassing and Its Limits
In cometary physics, we know that sublimation—the process where ice turns into gas as it is heated by the sun—can generate thrust, causing comets to accelerate slightly.
However, this type of outgassing usually produces irregular and chaotic motion, with the jets of gas coming from uneven areas of the comet’s surface.
3I/ATLAS, however, didn’t follow this expected behavior.
NASA’s official explanation was that 3I/ATLAS experienced asymmetric outgassing, where irregular surface features created jets that happened to align with the object’s direction of travel.
While this might seem plausible at first glance, the numbers didn’t add up.
For outgassing to produce the level of acceleration we observed, the comet would have had to eject a massive amount of material.
The coma— the cloud of gas and dust surrounding the nucleus—didn’t show significant expansion, and the gas production rates were moderate, nothing close to what would be needed to explain this acceleration.
Even more puzzling, the expected outgassing would require ejecting approximately 60% of the object’s mass—something that would have been visible in the form of large gas plumes and a significant coma expansion.
Yet none of that was observed.
The acceleration was simply too smooth, too sustained, and too directional to be explained by natural processes alone.
The Evidence for Propulsion
Here’s where things start to get really interesting.
The acceleration wasn’t just random.
It was applied in the direction of travel along the velocity vector—exactly as you would do if you wanted to speed up a spacecraft or adjust its trajectory.
This is trajectory optimization—essentially, powered flight.
It’s as if the object was using some form of propulsion to steer itself, and not just a comet simply reacting to solar radiation.
We’re talking about a controlled process, not an incidental result of surface ice sublimating.
The acceleration was gradual, building up over 18 hours, peaking near perihelion, and then tapering off.
The fact that this happened so precisely, timed with the closest approach to the sun, suggests some form of active control.
This is no ordinary cometary behavior; this is propulsion.
The Theories and the Mathematical Inconsistencies
Let’s consider some alternative explanations.
The first theory suggests that there might have been subsurface pressure release—trapped volatiles beneath the surface venting explosively through cracks.
This could explain the directionality of the thrust, but there are two major problems: first, there was no infrared evidence to suggest a hot spot consistent with such a release, and second, this would require an enormous amount of gas to be vented, which we didn’t observe.
Another theory posits that 3I/ATLAS’s rotation could have aligned certain vents with its direction of travel, causing pulses of thrust in the same direction.
But the acceleration was smooth and continuous for 30 hours—much longer than the rotational period, so this theory doesn’t hold up either.
Finally, we have the theory of shape effects—maybe the object’s irregular shape focused the venting in a specific direction.
While this could theoretically work, the necessary asymmetry would have to be extreme, and even then, it couldn’t produce continuous, directional acceleration.
Here’s where the math becomes particularly troubling.
For a 400-meter object to accelerate by 300 m/s purely through outgassing, it would need to eject about 60% of its mass.
That’s highly improbable—especially since we saw no evidence of such an enormous mass loss.
The Hubble Space Telescope also observed 3I/ATLAS throughout its perihelion passage, and the coma didn’t expand significantly.
The gas production rates were consistent with solar heating, but not nearly enough to explain the acceleration.
A Radical Possibility: Artificial Propulsion
Given all these anomalies, one possibility that must be considered is artificial propulsion.
If 3I/ATLAS was using something other than ice sublimation to produce thrust—such as an ion drive or chemical propulsion system—it could achieve the observed acceleration without ejecting large amounts of mass.
Ion drives, for instance, can achieve exhaust velocities up to 10 times higher than simple outgassing.
This would explain how the object could produce the required thrust while keeping mass ejection to a minimum—possibly below the detection threshold of current instruments.
More importantly, this would also explain the sustained, precise, and directional nature of the acceleration we observed.
The object would not just be a comet passing through our solar system—it would be a probe equipped with advanced propulsion technology.
