Everything scientists have gleaned so far about interstellar comets like 3I/ATLAS, they've gleaned by looking at them through a telescope.
And what a variety of telescopes scientists have at their disposal today.
More on 3I/ATLAS
3I/ATLAS is a comet that originated from deep space, and is passing through our Solar System.
Since its discovery on 1 July 2025, the comet has been observed and photographed by our most powerful telescopes on Earth and in space, including by the Hubble Space Telescope and the James Webb Space Telescope.
3I/ATLAS has even been photographed by spacecraft on Mars, giving astronomers the chance to keep track of it while it's temporarily hidden from view from Earth.
But what if we could launch a spacecraft to go and study an interstellar comet up close?
A team of scientists are working on how to do exactly that. What's more, they say it's perfectly possible.
Studying a piece of an alien world
A team from the Southwest Research Institute in San Antonio, Texas, USA, says they've completed a mission study showing how a spacecraft could fly by an interstellar comet.
If such a flyby could be achieved, it could provide even more insight into these mysterious, scientifically illuminating objects.
Comets and asteroids are primordial, ancient relics left over from the formation of our Solar System, so studying them can tell scientists a lot about how our Solar System formed and what its early conditions were like.
Interstellar comets like 3I/ATLAS come from outside our Solar System, having originated around a star elsewhere in the Galaxy.
That means these deep-space relics provide the chance for up-close study of samples of planet-forming building blocks around distant stars.
Building an interstellar comet mission
SwRI scientists looked at mission design, scientific objectives, payload and key requirements for a spacecraft that could launch and observe an interstellar comet up-close.
The team have even said that 31/ATLAS could have been intercepted and observed by their proposed spacecraft.
So far, three such interstellar objects have been found in our Solar System: 1I/‘Oumuamua in 2017, ISC 2I/Borisov in 2019 and 3I/ATLAS in 2025.
But new observatories like the Vera Rubin Observatory, which began its scientific campaign in 2025, could help astronomers find many more in the next decade.
That means a new era of discovering and studying interstellar comets and asteroids could be upon us
"These new kinds of objects offer humankind the first feasible opportunity to closely explore bodies formed in other star systems," says SwRI Associate Vice President Dr. Alan Stern, a planetary scientist who led the study project.
"An ISC flyby could give unprecedented insights into the composition, structure and properties of these objects, and it would significantly expand our understanding of solid body formation processes in other star systems."
Interstellar mission objectives
So what would a mission to visit an interstellar comet look like, and what would be its science goals?
Scientists say numerous interstellar objects could be passing between Earth and the Sun every year. As many as 10,000 may pass within Neptune’s orbit in a year.
The study looked at design challenges, costs, and what instruments would need to be included on the spacecraft.
The team say the trajectory of interstellar objects as they pass through the Solar System means we don't currently have the technology to send a spacecraft to orbit them, but a flyby is possible.
"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," says SwRI’s Matthew Freeman, the study’s project manager.
"The proposed mission would be a high-speed, head-on flyby that would collect a large amount of valuable data and could also serve as a model for future missions to other interstellar comets."
Key to any such mission would be learning more about the physical properties of the interstellar object, as this could help scientists decipher its formation and evolution.
It could also help determine how the object had been sculpted and moulded by its journey through deep space.
Scientists would also want to get a good look at the object's coma, which is a cloud of gas that forms around a comet's head as its ices melt and evaporate into space.
Is it really possible?
Just how likely is it that we could launch a spacecraft that would be able to perform a close flyby of an interstellar object speeding through our Solar System?
The SwRI team say they've created computer software that looked at a hypothetical population of interstellar comets, then calculated how much energy would be needed to get a spacecraft from Earth to the path of the comet.
They say the software shows a 'low-energy rendezvous trajectory is possible, and in many cases would require less launch and in-flight velocity change resources than many other Solar System missions'.
SwRI orbital mechanics specialist Dr. Mark Tapley used the software to calculate the trajectory that such a spacecraft could have taken from Earth to 3I/ATLAS.
He says the spacecraft designed by the team could have reached it.
"The very encouraging thing about the appearance of 3I/ATLAS is that it further strengthens the case that our study for an interstellar comet mission made," says Tapley.
"We demonstrated that it doesn’t take anything harder than the technologies and launch performance like missions that NASA has already flown to encounter these interstellar comets."
