Scientists Admit Origins of Comet 3I/ATLAS May Remain Unknown

Scientists studying the interstellar comet 3I/ATLAS have acknowledged that its origins might forever remain a mystery, describing it as “like a ghost from space.” Discovered on July 1, 2025, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile, this comet has drawn significant attention due to its unusual characteristics. Its highly hyperbolic orbital path indicates that it is not bound by the gravity of our Sun, confirming its origin from outside the Solar System.

Despite extensive observations, including efforts from some of the most advanced telescopes, researchers now believe pinpointing the exact source of 3I/ATLAS may be impossible. The challenges of time and the vastness of the galaxy contribute to this dilemma. A recent analysis revealed that tracing the comet’s trajectory through the Milky Way over millions of years presents significant difficulties. The object is thought to have been ejected from its original star system billions of years ago, with numerous stellar encounters likely scattering it further across space.

Challenges in Tracing Cosmic Origins

The complexity of 3I/ATLAS’s path has led scientists to conclude that its origin star remains unknown. The comet’s high excess velocity and active cometary nature make it a valuable subject for study, yet the multitude of stars and gravitational interactions it has encountered complicates the effort to reconstruct its past. As noted in a summary, “Its unusually high excess velocity… makes it a key probe…but its origin star is unknown.”

The research team highlighted that over millions of years, a comet could interact with various structures in the galaxy, including spiral arms, which could significantly alter its trajectory. This series of cosmic events has rendered the origin trail of 3I/ATLAS nearly impossible to follow.

Scientific Insights and Future Trajectory

While the birthplace of 3I/ATLAS may be lost to time, the comet still provides a wealth of scientific data. Observations made by the James Webb Space Telescope (JWST) and other infrared instruments have revealed that its coma—a cloud of gas and dust surrounding the nucleus—is predominantly composed of carbon dioxide. The ratio of CO2 to H2O is among the highest ever recorded for a comet, presenting unique opportunities for research.

Moreover, 3I/ATLAS is larger and brighter than previous interstellar objects, making it an especially appealing target for astronomers. As outlined in a recent article, the comet is expected to pass within the orbit of Mars and reach its closest approach to the Sun around late October 2025. After this perihelion, it will depart the Solar System, leaving scientists with more questions than answers.

The original article from New Scientist emphasizes that scientists may “never figure out where [3I/ATLAS] came from.” Without a recognizable parent star and with numerous potential gravitational influences, the comet’s history remains obscured. One lead researcher remarked on the unpredictable nature of cosmic travel, indicating that a comet’s journey through the galaxy can significantly alter its path.

3I/ATLAS serves as a reminder of both the richness of our cosmic neighbourhood and the limitations of human understanding. As one astronomer aptly put it, the comet is “a time capsule from another system.” Its brief visitation invites us to reflect on the mysteries of the universe and the endless possibilities it holds.