Is 3I/ATLAS a ‘serial killer’?: Scientist

Benevolent interloper or interstellar poison pill?

With 3I/ATLAS set to fly by Earth in two weeks, Harvard professor Avi Loeb is debating whether our interstellar visitor is friend or foe — an answer that potentially lies in its chemical makeup.

“There is much more methanol than hydrogen cyanide,” the astrophysicist told The Post. “In principle, methanol is an important agent for the origins of life.”

He added, “And on the other hand, the hydrogen cyanide at large concentrations is a poison.”

This comes as recently-released images by the European Space Agency’s Juice spacecraft taken last month show the comet sporting two tails and sublimating a large amount of gases following its closest approach to the sun, reported IFL Science.

In a new post published on Medium, the astrophysicist discussed what the chemical composition of said gas plume and other parts of the comet might reveal about its nature.

Loeb referenced observations by the Atacama Large Millimeter/Submillimeter Array (ALMA), a radio telescope in Chile that detected amounts of methanol and hydrogen cyanide in the cosmic body over the fall, per Loeb.

The researcher told The Post this was significant because methanol is “a building block for amino acids and sugars that are used for organic chemistry of life.”

“Young stars have a lot of methanol, and that was observed in the past two and a half decades,” Loeb explained.

He noted in the blog that in 2006, the MERLIN array of radio telescopes at the Jodrell Bank Observatory discovered a methanol cloud near a newly-formed star. Meanwhile, in 2016, ALMA picked up the chemical in a “planet-forming disc” encircling the young star TW Hydrae.

On the other hand, ATLAS also boasted levels of hydrogen sulfide, which was used as a poisonous chemical weapon by France, the United States and Italy in World War I.

Loeb quipped that while “on a blind date with an interstellar visitor, it is prudent to observe the dating partner and decide whether it could have seeded life on Earth” or “whether it represents a serial killer spreading poison” — like an intergalactic cyanide tablet.

Thankfully, he speculated that ATLAS was likely “friendly” given the anomalously large ratio of methanol to hydrogen-cyanide production, which was one of the highest observed in any comet.

Loeb believed that the celestial snowball could have even seeded life in other galaxies.

“If the solar system didn’t have the building blocks, it could have gotten them from the visits of objects like 3I/Atlas in the early solar system,” he told The Post.

In fact, Loeb previously speculated that Earth had been pollinated by multiple “interstellar gardeners” from advanced civilizations throughout its 4.6 billion existence — something we wouldn’t have noticed, as humans have only been monitoring the sky for said objects for a decade or so.

Of course, the scientist, who has long speculated over ATLAS’ artificial origins, claims that these finds don’t rule out its potential extraterrestrial origins.

He told the Post that the chemical composition suggests a possible fuel source, explaining, “You can imagine many ways by which fuel that is being consumed ends up producing methanol or in this way.”

This jived with Loeb’s observations last month surrounding ATLAS’ “complex jet structure,” which he speculated could be evidence of rocket thrusters on a spacecraft.

Loeb hopes that ATLAS’ chemical composition will become clearer with the release of new intel from telescopes, including a full dataset by Juice slated to be disclosed in February 2026.

Meanwhile, the James Webb Space Telescope is slated to snap a comet this month, perhaps close to when it makes its closest approach to Earth on December 19.