Ancient Interstellar Visitor 3I/ATLAS: Isotopic Evidence for Formation in the Milky Way's Early Thick Disk
To the point
3I/ATLAS is an interstellar comet about 10–12 billion years old, likely formed in the Milky Way long before the Sun, and its unusual carbon and hydrogen isotope signatures plus deuterium-rich water point to birth in cold interstellar space with carbon- and water-rich building blocks, according to Cordiner, Taylor, and Seligman.
