A research recently published in the Monthly Notices of the Royal Astronomical Society brought new information about the formation and origin of the interstellar comet 3I/ATLAS. This celestial body, which was the third external visitor to the Solar System detected by science, revealed secrets about its remote origin.
As it approached the Sun and began its journey away from planetary neighborhood, the comet underwent an intense process of material release. This event allowed scientists to meticulously examine the internal chemical composition of this celestial object, uncovering secrets preserved since its birth in a distant part of the Universe.
To analyze the expelled material, researchers from the University of Northumbria, located in the United Kingdom, used a modern spectrograph installed on the William Herschel Telescope, situated in Spain. This high-precision instrument captured the light emitted by the gases in the comet's tail, allowing for the identification of five chemical substances released simultaneously during the eruptions of the space visitor.
Among the components identified by the equipment were molecules of nitrogen, carbon monoxide, carbon dioxide, water, and hydrocarbons. By accurately mediating the proportion between nitrogen and carbon monoxide, the scientific team was able to estimate the approximate temperature at which the object was originally synthesized in its system of origin.
The findings indicated that 3I/ATLAS originated under conditions of extreme cold, with temperatures below minus 240 degrees Celsius. This data suggests that the comet developed in the coldest and most peripheral areas of its native stellar system, in a region analogous to the Oort Cloud or the Kuiper Belt around our Sun.
The large amount of gaseous nitrogen corroborates this hypothesis, since this element can only remain stable in environments where the heat from the central star is almost nonexistent. Scientists emphasize that studying these interstellar fragments offers a unique chance to understand the raw material of other worlds without the need to send probes to unreachable distances.
The investigation also progressed technically by mapping the chemical changes along the comet's tail as it interacted with solar winds. The precision achieved demonstrates how new optical instruments are expanding the capacity to study small celestial bodies that traverse space at high speed, quickly and unexpectedly.
However, despite the advances in the study of 3I/ATLAS, science faces a statistical limitation due to the small amount of comparative data. As explained by amateur astronomer Cristóvão Jacques, founder of the SONEAR Observatory, in an interview with Olhar Digital News some months ago: 'We have observed this type of object only three times. It is too little to draw broader conclusions.'
This limited sample makes it difficult to precisely determine the trajectory and origin of the space visitor. Although the chemistry of 3I/ATLAS provides a profile of its formation environment, it does not point to its exact location in the galaxy. For Jacques, identifying the natal star 'would allow us to better understand the environment in which it formed and compare it with what we observe today, based on analyses made on Earth.' However, he believes this information will probably never be determined with accuracy, stating: 'Knowing which specific star gave rise to this object is extremely difficult, perhaps impossible.'
This scenario of data scarcity should change drastically with the commissioning of the Vera C. Rubin Observatory in Chile, expected at the end of June. There is an expectation among astronomers that, driven by the scanning power of this new astronomical complex, the detection rate will increase considerably, making it possible to discover at least one new interstellar visitor annually and significantly expanding the catalog of objects available for study.
Equipped with an 8.4-meter diameter mirror and the largest digital camera ever created for astronomy, boasting an impressive 3.2 gigapixels, the observatory will conduct the Legacy Survey of Space and Time (LSST). Every few nights, the system will map the entire visible sky of the southern hemisphere with great sensitivity, capable of identifying faint and fast-moving celestial bodies that previously went unnoticed.
For Bruno Quint, a doctor in astronomy from the University of São Paulo (USP) and operations scientist at the observatory, the new complex will be 'a machine for discoveries' and will revolutionize the way science studies the Cosmos. In his participation in the Olhar Digital News program, during the launch of the first test images of Vera Rubin, the astronomer pointed out that even in the commissioning phase, the telescope registered 1,000 asteroids in a single night, illustrating the impact of the initiative over its planned 10 years of operation.
This massive detection capability will also bring a new methodological model. According to Quint, previously scientists examined only small parts of the sky looking for specific targets, comparable to looking for a needle in a haystack. He compares: 'What Rubin will do is take that haystack, shake it, throw a bunch of needles on the ground, and we will have to think about what to do with them.'
In practice, this unprecedented volume of data will function integrated into a real-time automated alert system. A statement informs that upon detecting any object with a hyperbolic trajectory typical of an external visitor to the Solar System, the observatory will issue immediate warnings to the global astronomical community. This agility will allow instruments focused on spectroscopic analysis, such as the William Herschel Telescope, to be instantly directed to the target, ensuring the detailed investigation of its internal chemistry before the object moves away from the Sun and disappears into deep space.