3I/ATLAS: An Interstellar Comet with Unusual Water and Carbon Abundances Suggesting an Ancient Origin

To the point

3I/ATLAS is an interstellar comet with an unusually high deuterium-to-hydrogen ratio and rich carbon and water content, indicating it formed in the cold outer regions of an ancient star system about 10–12 billion years ago and was later ejected into interstellar space, a conclusion supported by JWST observations from Martin Cordiner, Paul Hartogh, and Ewine van Dishoeck, though its exact origin remains uncertain.