Overview
- A NASA Goddard team’s analysis of JWST near‑infrared spectra, corroborated by earlier ALMA radio measurements, finds about 30 times more deuterium in 3I/ATLAS’s water than in Solar System comets.
- The same JWST data show an unusually low ratio of carbon‑13 to carbon‑12, a signature that astronomers interpret as consistent with material formed early in the galaxy’s history.
- Scientists infer from those isotopes and the comet’s reconstructed trajectory that 3I/ATLAS likely formed in an extremely cold environment roughly 10–12 billion years ago, though the age estimate remains provisional.
- Researchers stress limits to the conclusion because the object was observed only during a brief flyby and because there are just three known interstellar visitors to compare, so single‑object results may not be representative.
- The Vera Rubin Observatory’s ongoing survey is expected to find many more interstellar objects in coming years, which will be needed to test whether 3I/ATLAS reflects a common early‑galaxy formation pathway or is an outlier.