A recent study has provided new insights into the age of the interstellar comet 3I/ATLAS, suggesting it may be significantly older than our solar system. The comet, which caught the attention of astronomers during its passage through our solar system in 2025 and earlier this year, has now left our solar system, but research into its composition continues.
A team of scientists published their findings in the journal Nature Astronomy, detailing their analysis of the comet’s chemical tail. Using the James Webb Space Telescope (JWST), researchers examined the comet’s coma as solar radiation warmed its icy core. They did not find evidence of an alien civilization but discovered ancient ice believed to have formed between 10 to 12 billion years ago, potentially making it more than twice the age of the Sun.
The JWST identified a significantly elevated deuterium-to-hydrogen (D/H) ratio in the comet’s methane gas, approximately 13 times higher than that of local comets like 67P. This finding suggests that the comet’s ice originally formed in a very cold and low-metallicity protostellar cloud that experienced intense cosmic ray bombardment before the formation of our solar system.
The study indicates that 3I/ATLAS likely originated from an ancient region of the Milky Way galaxy, formed around a young star long before heavier elements were distributed in our local universe due to dying supernovae. This research provides a rare opportunity to explore material from outside our solar neighborhood, enhancing our understanding of cometary origins and the early solar system.
As scientists continue to analyze the data collected from 3I/ATLAS, further insights into interstellar objects and their histories may emerge, shaping our understanding of cosmic evolution.
