3I/ATLAS Has An Extreme Taste For Heavy Water

More and more details about 3I/ATLAS are filtering through the scientific process as time goes on. Our third known interstellar visitor attracted the attention of some of the most powerful observatories in the world when it was discovered in July 2025, and some of those telescopes found something peculiar - the isotopes it contained appeared different. A new paper submitted to The Astrophysical Journal Letters (and available in pre-print on arXiv) by Kenji Furuya of the RIKEN Pioneering Research Institute in Japan and his co-authors, shows how that isotopic discrepancy is likely due to the “low-metallicity” of the stellar nursery 3I/ATLAS was born in.