Interstellar comet 3I/ATLAS has 13 times more deuterium than a famous Solar System comet, hinting at its 7-billion-year-old origins

Interstellar object 3I/ATLAS may have formed more than 7 billion years before our Sun was born. A new study using NASA's James Webb Space Telescope has uncovered unusual chemical clues that could reveal the comet's ancient origins and the conditions in which it formed. Its deuterium-to-hydrogen ratio was also 13 times higher than that of comet 67P/Churyumov-Gerasimenko.