Scientists gear up for close-up look at interstellar visitor 3I/ATLAS, with comet set to fly past Mars

Astronomers on fri testament eventually acquire a chance to keep interstellar visitor 3I/ATLAS up close, when the comet flies past Mars, giving scientists an opportunity to glean insights from an ancient deep space relic.

An object of intense speculation and controversy, 3I/ATLAS, understood to be the third visitor to the Solar System from another star system, got the entire scientific community talking after initial observations of the celestial object prompted Harvard astrophysicist Avi Loeb to suggest that it could be an artificial object, possibly sent by an extraterrestrial civilization.

First spotted on July 1, 2025, 3I/ATLAS was found to be moving through the Solar System at almost twice the velocity of previous interstellar visitors 'Oumuamua and Comet Borisov, and the initial lack of a visible comet tail and some unusual properties prompted Loeb to speculate that it could be alien technology.

The suggestion by Loeb, known for his outlandish claims, gained significant traction on social media, but was quickly dismissed by the scientific community at large.

"It looks like a comet. It does comet things. It very, very strongly resembles, in just about every way, the comets that we know," Tom Statler, NASA's lead astronomer for Solar System small bodies told The Guardian, adding, "It has some interesting properties that are a little bit different from our Solar System comets, but it behaves like a comet. And so the evidence is overwhelmingly pointing to this object being a natural body. It’s a comet."

Now, with the 3I/ATLAS set to fly past Mars on October 3, astronomers will be able to use existing spacecraft and probes sent to the Red Planet to observe the comet, which could yield invaluable scientific insights.

As the fly-by happens, missions already at Mars—including UAE's Hope probe, NASA's MAVEN spacecraft, and ESA's Mars Express and Trace Gas Orbiter—will observe the comet in ultraviolet and infrared light to analyze its chemical makeup.

Even NASA's Curiosity and Perseverance rovers, which are on the Martian surface, will attempt to observe the comet as it flies past.

After its date with Mars, 3I/ATLAS will disappear from the view of Earth-based telescopes until early December 2025 as its trajectory will take it around the opposite side of the Sun, obscuring it from view.

Unfortunately for scientists, it is during this time that the comet will be at its most active, but astronomers are hopeful of leveraging solar observatories like the Parker Solar Probe to observe the comet around this time.

Further observations using spacecraft around Jupiter—such as NASA's Europa Clipper and the ESA's JUICE mission—are planned for late 2025 and early 2026.

Beyond the fact that 3I/ATLAS is only the third-own interstellar visitor, scientists believe the comet to be a remnant of the Milky Way's 'cosmic noon', originating from the galaxy's 'thick disk' around 9-13 billion years ago during a period of intense star formation.

"If confirmed, 3I will provide a means to explore the stellar and planetesimal formation process, and its astrobiological implications, in an early period of galactic history," a paper by MIT-educated physicist and former NASA scientist Thomas Marshall Eubanks says.

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