For now, everything we know about interstellar comets such as 3I/ATLAS comes from watching them through telescopes. But a group of planetary scientists believes that soon, we might actually be able to visit one.
A visitor from deep space
Discovered on 1 July 2025, 3I/ATLAS is a comet that originated far beyond our Solar System. It’s been tracked by the Hubble Space Telescope, James Webb Space Telescope, and even cameras aboard spacecraft orbiting Mars.
Recently, NASA’s SPHEREx mission captured a detailed view of 3I/ATLAS between 7–15 August 2025, revealing new clues about its unusual composition.
But what if we didn’t have to observe from afar? What if we could send a spacecraft to meet it face-to-face?
The mission concept
A team at the Southwest Research Institute (SwRI) in San Antonio, Texas, has completed a detailed mission design study showing that a spacecraft could fly by an interstellar comet like 3I/ATLAS — and they say it’s entirely feasible.
“These new kinds of objects offer humankind the first feasible opportunity to closely explore bodies formed in other star systems,”
— Dr. Alan Stern, SwRI Associate Vice President and principal investigator of the study.
Comets and asteroids are time capsules from the early Solar System. Studying interstellar versions of these relics could give scientists a unique glimpse into how planets form around other stars — and how those systems compare to our own.
How we’d get there
The SwRI team examined everything from trajectory design and spacecraft payload to energy requirements and onboard instruments. Their simulations show that a low-energy rendezvous trajectory is possible — one that would demand no more propulsion than many missions NASA has already flown.
Dr. Mark Tapley, an orbital mechanics expert at SwRI, used specialized software to model how a spacecraft could intercept 3I/ATLAS. His conclusion?
“It doesn’t take anything harder than the technologies and launch performance NASA has already demonstrated to encounter these interstellar comets.”
Project manager Matthew Freeman adds that while orbiting such a fast-moving object isn’t yet possible, a high-speed flyby would still be revolutionary:
“The trajectory of 3I/ATLAS is within the interceptable range of the mission we designed, and the scientific observations made during such a flyby would be groundbreaking.”
What we could learn
A flyby mission could study an interstellar comet’s composition, structure, and coma — the cloud of gas and dust that forms as sunlight heats the nucleus. It would reveal how such objects are shaped by eons of travel through interstellar space, and how their chemistry compares to comets born in our Solar System.
Dr. Stern emphasizes that such encounters could “significantly expand our understanding of solid body formation processes in other star systems.”
A new era of discovery
So far, astronomers have identified only three interstellar objects:
1I/‘Oumuamua (2017)
2I/Borisov (2019)
3I/ATLAS (2025)
But that number may soon grow. The Vera C. Rubin Observatory in Chile — set to begin its decade-long survey of the southern sky in late 2025 — will likely uncover many more.
With better detection, faster computing, and improved propulsion, missions like SwRI’s could usher in the first direct exploration of alien worlds adrift between the stars.
“An interstellar comet flyby could provide unprecedented insights,” says Stern. “It would open an entirely new chapter in our exploration of the cosmos.”
