Interstellar Comet 3I/ATLAS is exceptionally alcoholic

The interstellar comet 3I/ATLAS is exceptionally alcoholic

By Jackie Flynn Mogensen edited by Claire Cameron

The interstellar comet 3I/ATLAS is the gift that keeps on giving. A glimpse of space beyond the solar system, it provides clues to our understanding of other stars, other worlds and the galaxy in which we live. Only three of these interstellar objects have been discovered, and by studying each of them, we learn more about what lies outside our cosmic neighborhood.

Last year, the comet was close to passing our sun, reaching speeds of more than 150,000 miles per hour at its closest point. This trajectory gave scientists the opportunity to observe the comet in detail, revealing that it is exceptionally alcoholic.

“Observing 3I/ATLAS is like taking the fingerprint of another solar system,” Nathan Roth, a research assistant professor at American University, said in a statement. “The details reveal what it’s made of, and it’s packed with methanol in a way we don’t usually see in comets in our own solar system.”

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When a typical comet approaches the sun, the ice inside the space rock turns to gas, leaving in its wake a trail of gases such as carbon monoxide, methane and ammonia, and sometimes a little methanol. But according to new measurements by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, the interstellar interloper is “highly enriched” in methanol – in fact, much more methanol than astronomers might have expected.

The discovery could offer clues to the origin of 3I/ATLAS: a question that has intrigued scientists since the comet’s discovery in July 2025. The research was published on the preprint server arXiv.org and has not yet been peer-reviewed.

Meanwhile, comet 3I/ATLAS continues its journey through our solar system and our spacecraft are still monitoring it. In February, a new image taken by the European Space Agency’s Jupiter Icy Moons Explorer spacecraft revealed that 3I/ATLAS, now beyond the sun, appeared as a “bright white egg-shaped object” as it passed, according to the agency.

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