NASA and its international partners are ramping up planetary defenses after a mysterious Manhattan-sized comet began behaving in ways that have scientists scratching their heads — and, in some cases, raising the possibility of something not entirely natural.

The cosmic object, known as Comet 3I/ATLAS, was first spotted on July 1 and has since exhibited a string of bizarre behaviors that prompted the International Asteroid Warning Network (IAWN) — a NASA-coordinated global coalition — to officially list it as a potential threat.

While there’s no immediate cause for panic, experts say the comet’s strange composition, trajectory, and emissions have forced them to treat it seriously.

So, this is what's happening, for the first time in history, an interstellar object namely 3I/ATLAS has been formally enrolled in a planetary defense–level observation campaign.

They’re calling it “a test of improved astrometry methods.” In other words, the object isn’t… pic.twitter.com/aAdnbOrBJL

— Dennis Blankshine (@Blankshine_IRL) October 21, 2025

3I/ATLAS, roughly the size of Manhattan Island, stunned astronomers when it was found emitting a rare alloy — nickel tetracarbonyl — at a rate of 4 grams per second, without any detectable iron. That compound, scientists note, has only ever been observed in human manufacturing, not in nature.

The comet also displayed an anti-tail, meaning that instead of trailing particles away from the sun, it was releasing jets pointed directly toward it — a highly unusual and unexplained phenomenon.

Adding to the mystery, researchers have detected non-gravitational acceleration and an anomalous orbital path that will carry the object close to Jupiter, Venus, and Mars before it slingshots near Earth’s neighborhood.

In response, NASA and IAWN have launched what they’re calling a “comet campaign”, scheduled from November 27 through January 27, aimed at refining detection and response techniques for potentially hazardous interstellar objects.

“To prepare for the campaign, we will hold a workshop on techniques to correctly measure comet astrometry,” IAWN said in a statement, referring to precision tracking methods used to calculate orbital movement and rotation.

Although officials have described the initiative as a “test of improved astrometry methods,” some astronomers and sky watchers have expressed concern that 3I/ATLAS simply isn’t behaving like a typical comet.

Among those intrigued by 3I/ATLAS is Harvard astrophysicist Avi Loeb, who has previously suggested that some interstellar objects may be artificial in origin. Loeb noted that the comet’s chemical emissions and acceleration patterns could point to an engineered probe rather than a random rock.

In a recent blog post, Loeb speculated that the object’s upcoming close approach to the sun — followed by a rapid change in trajectory — might indicate an intentional gravitational slingshot maneuver, similar to how spacecraft use planetary gravity to alter their speed and direction.

“If 3I/ATLAS is a massive mothership, it will likely continue along its original gravitational path and ultimately exit the Solar System,” Loeb wrote.

Photo credit: Flickr