Interstellar object 3I/ATLAS provided scientists with an exceptionally rare opportunity to study the nature of other planetary systems beyond our own. It was first discovered in July of last year, heading straight past the Sun and making its closest approach to our star in late October.
It’s been speeding out of the solar system ever since, releasing copious amounts of carbon dioxide and water vapor that potentially date back billions of years.
But scientists think it’s technically still possible to send a probe and have a closer look, as Space.com reports. It’s admittedly a long shot: the mission would have to launch by 2035 to catch up with 3I/ATLAS by 2085, at which point it will be over 700 times the distance between the Sun and Earth away from us, or over four times the distance NASA’s Voyager 1 spacecraft has covered over the last 48 years.
To gain enough speed, such a probe would have to perform close flybys of the Sun, making use of the Oberth effect to borrow energy from the star’s extreme gravitational field. As former NASA staffer and Space Initiatives chief scientist Marshall Eubanks told Space.com, it’s common for spacecraft to use the effect. However, as detailed in a new yet-to-be-published paper, he and his colleagues proposed performing a major burn during the closest approach to reach massive levels of acceleration — a delta-V, or a change in velocity, of over five miles per second.
Besides reaching potentially record-breaking speeds for any spacecraft, it would also have to endure searing temperatures as it brushes by the Sun.
After its daring solar flyby, the spacecraft would then need to perform several flybys of Venus to speed up even more, not unlike NASA’s Parker Solar Probe. In their paper, the researchers propose using a “refueled Starship Block 3” in low-Earth orbit, referring to SpaceX’s enormous launch platform, which would have “sufficient performance for such a mission.”
But whether it would be worth the effort to careen after 3I/ATLAS for decades remains debatable. The interceptor would also only be able to perform a flyby some 50 years from now due to the difference in velocities, greatly undermining the usefulness of such a major undertaking.
Fortunately, as more powerful space telescopes like the Vera C. Rubin Observatory come online, 3I/ATLAS probably won’t be the last interstellar object to be detected cruising by in the near future.
“We’ll just have to see,” Eubanks told Space.com. “Maybe after, say, ten interstellar objects have been found, 3I will seem commonplace and it won’t seem worthwhile to mount an expedition to chase it.”
However, any future interstellar objects should be chased by spacecraft that are already in orbit, Eubanks and his colleagues argued.
“There are better mission architectures, using a probe already in orbit in space, which would intercept an interstellar object around perihelion in much less time, rendering an Oberth unnecessary,” Adam Hibberd, Optimum Interplanetary Trajectory Software creator and coauthor of the latest paper, told Space.com.
Conveniently, the European Space Agency is already planning to launch its Comet Interceptor mission as soon as late 2028 and “park” it while it awaits its target, opening the door for studying future interstellar visitors.
“I feel quite confident that when we develop the ability to reach these interstellar objects, there will be a strong desire to directly explore at least some of them,” Eubanks told the outlet.
More on 3I/ATLAS: 3I/ATLAS Spraying Material as It Exits the Solar System