Virtual Telescope Project
Image of 3I/ATLAS on December 30, 2025, obtained from nine 120-second exposures taken with the Virtual Telescope Project telescope in Manciano, Italy
The interstellar comet 3I/ATLAS continues to surprise scientists, this time by showing unusually high levels of methanol in the gas cloud that surrounds it.
The discovery, based on observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) and released by the National Radio Astronomy Observatory (NRAO), suggests that this mysterious visitor from outside the Solar System formed under conditions very different from those of the comets we know.
As it approached the Sun, the ice on its surface began to vaporize, releasing gas and dust. This material gave rise to the so-called comathe diffuse, bright cloud that surrounds the comet’s nucleus. It was precisely through the analysis of this cloud, using high-precision radio telescopes, that researchers were able to identify the chemical composition of the object.
Among the compounds detected, methanol stood out for its unusual abundance. Although this molecule — a simple alcohol — is not rare in Space, its concentration in 3I/ATLAS is significantly higher than that recorded in comets formed within our Solar System. Scientists also found that the ratio between methanol and hydrogen cyanide is very different from usual, which suggests an origin marked by a different chemical environment.
According to researchers, this chemical imbalance could indicate that the comet formed in colder regionsor in a planetary system with chemical characteristics different from those that gave rise to the icy bodies of our own system. The hypothesis makes 3I/ATLAS particularly valuable for studying the diversity of materials and formation processes that exist elsewhere in the galaxy, according to the NRAO.
Methanol is often found in icy dust grains present in interstellar clouds. Throughout the process of forming stars and planets, these particles can be incorporated into comets and other small celestial bodies. But, in the case of 3I/ATLAS, the observed quantity draws attention as it clearly exceeds the values normally found in local comets.
Although there is currently no possibility of studying the object directly, the instruments available on Earth allow scientists to obtain a detailed characterization of its composition. And it is precisely this remote analysis that is transforming 3I/ATLAS into a rare natural laboratory to better understand how icy bodies form outside the Solar System and to what extent they may differ from those we know.
