Interstellar Comet 3I/ATLAS Points to a Cosmos Older Than the Solar System

New observations of interstellar comet 3I/ATLAS from JWST and other telescopes confirm its interstellar origin and reveal chemical fingerprints—a red, cosmic-ray–processed surface; unusually high deuterium abundance and a carbon-12 to carbon-13 ratio far lower than Solar System values—that point to formation in a cold, primitive environment long before our Solar System, making 3I/ATLAS billions of years older than the Sun; its orbit alone cannot determine its age.