Space & Astronomy

Enigmatic interstellar visitor 3I/ATLAS yields intriguing new discovery

By T.K. Randall
March 12, 2026

Image Credit: NASA, ESA, STScI, D. Jewitt (UCLA), M.-T. Hui (SHAO). Image Processing: J. DePasquale (STScI) By now, just about everyone will have heard about 3I/ATLAS, an interstellar object - thought by most scientists to be a comet - that was discovered passing through our solar system last year.

Most of the intrigue surrounding this object came courtesy of a vocal minority - including Harvard's Prof Avi Loeb - who believed that there was a reasonable chance that 3I/ATLAS could in fact be an artificially constructed object controlled by an advanced extraterrestrial civilization.

Evidence of this came in the form of various anomalies concerning the object's speed, composition and trajectory that Loeb in particular had interpreted as evidence of artificial construction.

When 3I/ATLAS reached its closest approach to the Earth and headed off back toward interstellar space, however, it quickly became apparent that there was nothing intelligent about it at all.That said, this intriguing interstellar interloper is still throwing up surprises - as evidenced recently when a new study using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile discovered that 3I/ATLAS is home to an anomalously large amount of methanol.

Considered a precursor to the development of life, methanol is found in other comets in our solar system but not in anywhere near as high an amount.

Its presence in 3I/ATLAS in such large quantities offers a hint at what the conditions might have been like in the distant solar system where this object began its journey through the cosmos.

"Observing 3I/ATLAS is like taking a fingerprint from another solar system," said study lead author Nathan Roth of American University.

"The details reveal what it's made of, and it's bursting with methanol in a way we just don't usually see in comets in our own solar system."

Source: Sky at Night

Tags: Interstellar