The interplanetary comet 3I/ATLAS is remarkably rich in a specific type of water that contains deuterium, meaning it came from somewhere colder and with lower levels of radiation than our early Solar System. 3I/ATLAS created quite the buzz as it flew through our Solar System. As just the third interstellar object (ISO) ever detected, what our instruments observed as it approached our Sun and began heading back to deep space provided tantalizing clues abo... [5081 chars]