Interstellar comet 3I/ATLAS pours water into space, JUICE reveals

Interstellar comet 3I/ATLAS is actively ejecting water vapor as it passes near the Sun, with an outflow of about two tons per second (roughly 70 Olympic swimming pools of water vapor per day), observed by ESA’s JUICE spacecraft using the MAJIS and JANUS instruments. Infrared detections of water vapor and carbon dioxide around perihelion show an extended coma, tail, and jets, offering a glimpse into materials formed around another star billions of years ago. The observations were unplanned and conducted in 2025, with data reaching Earth in 2026, highlighting JUICE’s capability to study interstellar visitors on its journey to Jupiter.