24/06/2026 04:37 - Tecnologia
An international investigation led by the University of Michigan (United States) has successfully deciphered one of modern astronomy's most fascinating chemical enigmas: the origin of interstellar comet 3I/ATLAS. Using the powerful ALMA observatory, located in Chile's Atacama Desert, scientists discovered that this mysterious wandering visitor formed in an extremely cold, isolated, and hostile region of the Milky Way, long before our own Sun was born.
The findings, published recently in the prestigious journal Nature Astronomy, confirm that 3I/ATLAS is the third confirmed interstellar object in history and possibly the oldest ever observed. With an estimated age of up to 11 billion years —more than double our solar system's 4.6 billion years— this harmless ball of ice and rock offers an unprecedented window into the chemistry of the primordial universe.
The key to the discovery lies in spectroscopic analysis of the frozen water carried by the comet. Astronomers detected extraordinarily high amounts of deuterium, also known as "heavy hydrogen." This chemical signature is irrefutable proof that the object consolidated under extremely low temperatures.
Deuterium is a stable isotope of hydrogen containing one proton and one neutron in its nucleus, unlike common hydrogen which only has a proton. Its presence in high proportions in a comet's water indicates formation under extreme cold conditions, where chemical reactions favor incorporation of this heavy isotope.
"The extremely high deuterium ratio tells us the comet originated in a corner of the galaxy considerably colder than our own cosmic environment," explained Teresa Paneque-Carreño, astronomer at the University of Michigan and lead author of the study. According to the physical models presented, the celestial body condensed even before its native system's star had formed.
While our Sun formed surrounded by other newborn stars that heated the primordial cosmic neighborhood, the parent star of 3I/ATLAS would have been much more solitary. This lack of external radiation allowed the comet to preserve its original volatile components intact throughout billions of years traversing interstellar space.
The comet was discovered in mid-2025, providing an ideal timeframe for space agencies like NASA and the European Space Agency (ESA) to coordinate global efforts. Multiple space and ground-based telescopes pointed their lenses at the icy rock during its trajectory:
| Date | Event |
|---|---|
| October 2025 | Mars flyby |
| December 2025 | Closest approach to Earth |
| March 2026 | Jupiter vicinity passage |
Although initial observations after perihelion passage (its closest point to the Sun) surprised scientists with its unusual blue glow, trajectory anomalies, and unusual gas emissions —even raising unfounded suspicions about possible artificial origins— ALMA observatory analyses buried any conspiracy theories. Data definitively confirms its completely organic nature.
Currently, the colossal space traveler is navigating well beyond Jupiter's orbit on an unstoppable hyperbolic trajectory. Due to its enormous speed —nearly 210,000 km/h— it's not gravitationally bound to the Sun, meaning it will continue its journey toward the depths of deep space and permanently leave our solar system, never to return.
Observation is now reserved exclusively for specialists equipped with high-complexity technology, but its legacy has rewritten what we know about galactic chemical evolution.
Interstellar objects are celestial bodies originating outside our solar system that traverse interstellar space. Before 3I/ATLAS, only two had been confirmed:
These cosmic visitors represent a unique opportunity to study the chemical composition of other planetary systems without needing to travel to them.
The Atacama Large Millimeter/submillimeter Array (ALMA) is a set of 66 radio antennas located in Chile's Atacama Desert at 5,000 meters altitude. It's one of the world's most powerful astronomical observatories for studying the cold universe, including molecules in interstellar space and planet and star formation.
Source: El Litoral | Published in Nature Astronomy
Alfredo S. Quiroga
