An in-depth analysis of images captured by Telescópio Espacial Hubble has revealed peculiar behavior in the interstellar comet 3I/ATLAS, the third confirmed visitor from outside our Sistema Solar. The object displayed highly structured jets of luminous material that, surprisingly, pointed directly at Sol, a phenomenon that intrigues astronomers and challenges conventional understanding of cometary dynamics.
The unprecedented observations were made possible by a rare celestial alignment that occurred in January 2026. Essa favorable geometric configuration provided scientists with a unique opportunity to study in detail the composition and activity of a celestial body formed in a distant star system, offering a glimpse into conditions elsewhere in the galaxy.
The discovery reinforces the importance of monitoring these cosmic travelers, who function as natural probes, bringing valuable information about the diversity of planetary building blocks existing in the universe.
A visitor from beyond our system
The journey of 3I/ATLAS through our Sistema Solar began to be tracked after its discovery in July 2025, carried out by the ATLAS asteroid impact warning system, in Chile. Desde the first observations, its trajectory proved unusual, and orbital calculations quickly confirmed that the comet followed a sharply hyperbolic orbit. The Esse path type is a clear signature of objects that are not gravitationally bound to the Sol, proving that it was a messenger from another star system. The comet reached its closest point to Sol, known as perihelion, in October 2025, at a safe distance of 1.36 astronomical units (AU), just beyond the orbit of Terra.
After bypassing Sol, the object made its closest approach to our planet in December 2025, passing at around 1.8 AU without posing any risk. The study of bodies like 3I/ATLAS is of immense scientific value, as they represent direct samples of primordial matter from other regions of Via Láctea. By analyzing their composition, structure and the way they interact with our Sol, researchers can compare the ingredients that formed our Sistema Solar with those of other systems, looking for universal patterns or fundamental differences in planetary formation.
The perfect geometry for observation
Key to capturing these extraordinary images was the specific planetary alignment of the January 22, 2026, Nessa date, the comet reached a point in its orbit known as “opposition,” where Terra positioned itself almost directly between it and Sol.
This configuration is extremely advantageous for observing dusty bodies, as the phase angle — the angle formed between the Sol, the comet and the observer at Terra — becomes minimal. In the case of 3I/ATLAS, this angle reached just 0.69 degrees.
Under these conditions, sunlight illuminates the dust ejected by the comet almost head-on, causing a backscattering effect known as an “opposition flare.” Esse phenomenon drastically amplifies the brightness of particles, making faint structures, such as jets and halos, much easier to detect and analyze.
Jets that defy knowledge
The most notable feature revealed in images of Hubble is a set of well-defined, collimated jets of dust and gas emanating from the comet’s unresolved nucleus. Diferentemente of traditional cometary tails, which are always pushed in the opposite direction to Sol by radiation and the solar wind, these structures pointed directly at our star. Advanced image processing, which uses algorithms to remove the symmetrical glow of the coma, made it possible to identify at least two distinct jets, separated by an angle of approximately 120 degrees. The Esse pattern suggests that material is being expelled from specific active regions on the core’s surface. The persistence of these shapes across multiple observations, combined with small variations, led scientists to estimate a rotation period of about 7.1 hours for the comet. Essa directional structure, technically called the anti-tail, indicates a complex interaction between the rotation of the nucleus, the location of its active sources and the sublimation of volatile ices, a behavior rarely seen with such clarity, especially in an object of interstellar origin.
What makes up comet 3I/ATLAS?
To decipher the engine behind this intense activity, astronomers used spectroscopy, a technique that breaks down the comet’s light to identify its chemical composition. The analysis revealed that the 3I/ATLAS coma is particularly rich in carbon dioxide (CO2).
This compound sublimates (turns from ice to gas) at very low temperatures, which explains why the comet was active even when it was far from Sol. Vapor of water and carbon monoxide were also detected, although in lower concentrations.
Complementary observations made by Telescópio Espacial James Webb added another piece to the chemical puzzle, with the detection of traces of carbonyl sulfide, a less common compound in comets from our own Sistema Solar.
This strong ejection of gases is also the cause of the comet’s “non-gravitational acceleration”, a small deviation from its orbital trajectory that occurs due to the thrust generated by the release of material, functioning as a natural jet propellant.
Visual details of the coma and anti-tail
Visually, the coma — the cloud of gas and dust that surrounds the nucleus — acquired a teardrop shape after passing through perihelion, extending for millions of kilometers. The prominent anti-tail directed towards Sol, in some of the processed images, measured up to ten times the apparent diameter of the coma itself, highlighting its magnitude.
Ground-based observatories, such as Gemini North, also recorded a subtle greenish hue in the coma. Essa color is a characteristic signature of the presence of molecules such as diatomic carbon (C2) and cyanogen (CN), which glow in this tone when they are excited by the ultraviolet radiation of Sol.
The likely origin of the cosmic traveler
The comet’s trajectory offers valuable clues not only about its current path, but also about its distant origins. Sua orbit has an eccentricity greater than 6, an extremely high value that definitively confirms that the comet does not belong to our Sistema Solar and that, after this passage, it will never return.
Traveling at a relative speed of approximately 60 kilometers per second, its trajectory suggests it originated in the “thick disk” of Via Láctea, a region of our galaxy that is home to older stars. Isso implies that 3I/ATLAS could be an incredibly old object, with a potential age of more than 7 billion years.
The future of monitoring
Currently on its journey back into interstellar space, 3I/ATLAS is progressively moving away from Sol and Terra, and its brightness continues to decrease. The comet will remain within reach of large professional telescopes until mid-2026, allowing the scientific community to continue to monitor its diminishing activity as it plunges back into the darkness and cold of deep space.
