Interstellar Comet 3I/ATLAS Could Be a 10-Billion-Year-Old Relic From the Early Galaxy
A Coruña, Spain – An interstellar comet that briefly visited our solar system, 3I/ATLAS, may be a remarkably ancient object - perhaps 10 billion years old – offering a unique glimpse into the formation of planetary systems in the early universe, according to a new, preliminary study. Researchers at the University of A Coruña used data from the European Space Agency’s Gaia mission to trace the comet’s trajectory back through time, attempting to pinpoint its origin through past stellar encounters.
The team meticulously mapped 3I/ATLAS’s path over the last 10 million years, identifying 93 potential close approaches to other stars within 500 parsecs (approximately 1,630 light-years), with 62 deemed statistically significant. However, the study found that none of these encounters considerably altered the comet’s orbit. ”None of these encounters produced any meaningful perturbation,” the team wrote in their paper, posted to the pre-print server arXiv. Even the closest encounter, with star Gaia DR3 6863591389529611264 at a distance of 0.30 parsecs (6.5 light-years) and a relative velocity of 35 km/s,resulted in a negligible velocity change of only 5 × 10−4 km/s.
This lack of gravitational influence suggests 3I/ATLAS didn’t originate from a recent stellar interaction. The researchers believe the comet likely originated from the Milky Way’s thin disk,a contrast to a previous hypothesis suggesting a possible origin in the thicker disk.
“Together, all data indicate that while 3I/ATLAS follows a thin-disk orbit in the solar neighborhood, it may nonetheless be an old object, consistent with ejection from a primordial planetesimal disk in an early-formed system, or from an exo-Oort cloud,” the team concludes, adding that its precise origin “remains undisclosed.”
The findings underscore the importance of continued study of interstellar objects like 3I/ATLAS. “What makes 3I/ATLAS unique is that it allows us to study the evolution of objects originating from other stellar systems – somthing we had only theorised about until now,” said Pérez Couto,Center for Research in Facts and Interaction Technologies researcher and team leader,in a statement. “Each observation is like opening a window into the Universe’s past.”
While its true origin may remain a mystery, 3I/ATLAS represents a rare opportunity to analyze material from a bygone era, potentially revealing clues about the conditions and processes that shaped the earliest planetary systems in our galaxy.
