A NASA space observatory captured signs of organic molecules associated with pre-biological chemistry being released by the comet 3I/ATLASan interstellar object that passed through the Solar System in 2025. Data obtained by the telescope SPHEREx show that compounds such as methanol, cyanide and methane — considered “building blocks” for reactions that may predate life as we know it — were detected in the material expelled by the comet as it approached the Sun and then passed close to Earth’s orbit.
The comet 3I/ATLAS was discovered on July 1, 2025 by the ATLAS automated sounding system, which monitors near-Earth objects, and shortly after was classified as one of the rare interstellar visitors — bodies that were born outside our Solar System and travel through the space between stars before crossing our cosmic environment.
Comet 3I/ATLAS
During its trajectory through the Solar System, 3I/ATLAS warmed up and released an active coma — the cloud of gas and dust characteristic of comets — that expanded and led to the release of complex organic compounds, including methanol, hydrogen cyanide and methane. These molecules, although not life in themselves, are widely considered fundamental chemical ingredients in processes that can lead to the formation of biological structures in conducive environments.
The telescope SPHERExlaunched in March 2025 with the aim of mapping the sky in infrared and studying the composition of celestial objects, was able to capture these chemical signatures between December 8 and 15, 2025, while the comet was on its way out of the Solar System.
Experts say these observations offer a rare window into primordial chemical composition of an object that likely formed around another star billions of years ago. The presence of these compounds suggests that complex organic matter — which may play a role in processes that predate life — is common in environments beyond our Solar System.
Although these results do not indicate the presence of life in 3I/ATLASthey reinforce the idea that the basic building blocks for the chemistry that sustains living organisms may be widely distributed in the universe.
