The European Space Agency's Jupiter Icy Moons Explorer (JUICE) has made a surprise discovery during its journey: an interstellar comet is ejecting enormous quantities of water into space. The object, designated 3I/ATLAS, was observed spraying the volatile substance at a remarkable rate.
According to Space.com, the comet is releasing enough water every day to fill approximately 70 Olympic-sized swimming pools. This observation was made using JUICE's sensitive instruments, which are designed to study the Jovian system but proved capable of analyzing the distant visitor. The detection provides a rare, detailed measurement of an object from beyond our solar system.
The JUICE spacecraft launched in April 2023 and is on a multi-year cruise to Jupiter. The encounter with 3I/ATLAS was an opportunistic observation, not part of the mission's primary objectives. The comet itself was only discovered in 2019 and is known to be on a hyperbolic trajectory, confirming its interstellar origin.
The finding is significant for planetary science as it offers direct data on the composition of an interstellar object. Water is a key ingredient for life and a major component of many solar system bodies. Measuring its abundance in an extrasolar visitor helps scientists understand how common such materials are across the galaxy and informs models of planetary system formation.
While the detection is a scientific bonus, it highlights the serendipitous nature of deep-space exploration. The primary goal for the JUICE mission remains the detailed study of Jupiter and its large, potentially ocean-harboring moons—Ganymede, Callisto, and Europa—beginning in 2031.