The interstellar comet 3I/ATLASthe third confirmed object to arrive in our solar system from another star, has just surprised the scientific community with a behavior that does not fit traditional models.
During its passage through perihelion—the closest point to the Sun— recorded a change in trajectory and acceleration that cannot be explained solely by gravitywhich generated new hypotheses and revived the debate about the nature of these cosmic visitors.
According to the Harvard astrophysicist Avi Loebwho analyzed the available data, the comet showed a “non-gravitational acceleration”that is, an extra force that pushes it beyond what known physical laws would predict.
What is striking is that this acceleration was not only radial, moving away from the Sun, but also transverse, as if something was deflecting it laterally.
Loeb suggests that the conventional explanation would be an intense expulsion of gases resulting from the sublimation of ice, a common phenomenon in comets, but he warns that the magnitude of the thrust exceeds what would be expected for a natural object: During the crossing to perihelion, the comet would have lost up to a tenth of its mass due to that process alone.
Different from its predecessors
The data ignited the discussion even more because 3I/ATLAS follows the line of other interstellar visitors that also showed irregularities, such as IMAURE in 2017.
Comet 3I/ATLAS does not represent a danger to Earth. Photo: Wikipedia (CC BY-SA 4.0)In this case, the comet even presented a color change towards blue—unusual for a body that heats up as it approaches the Sun—which suggests a different composition from that of typical comets in the solar system.
Unlike Borisovthe second interstellar object detected, 3I/ATLAS did not offer “calm” behavior: it appears to be disintegrating faster than expected, ejecting material on a large scale and modifying its course.
The hypothesis of extraterrestrial life: Real or delusion?
The New York Post, which took up Loeb’s study, highlighted that Some scientists are already wondering if it is really a comet or something else.
Loeb insists that the most reasonable hypothesis is still the natural one, but does not rule out the need to “keep an open mind” given the possibility that we are facing interstellar technology, as he already raised in the past with ʻOumuamua.
The unusual tone of comet 3I ATLAS.Most astronomers reject that idea, but acknowledge that the information available is still limited: the comet was hidden behind sunlight during the key moment of its approach.
Perihelion occurred on October 29, and as 3I/ATLAS begins to move away from the Sun, the window for obtaining data narrows: By the end of the year it will be too far away to be studied in detail.
Does not pose any risk to the Earth —its minimum distance will be about 270 million kilometers—, but it does leave an open question: why do the three interstellar objects detected so far behave so differently than expected?
If it is an extraterrestrial spacecraft, 3I/ATLAS would arrive on Earth in mid-December. Photo: Screenshot.Science now looks at the sky with the same intrigue as it did centuries ago, and a comet coming from another star has just reminded us of it.
