The comet 3I/ATLAS is a fascinating discovery from beyond our solar system. It’s releasing enough water to fill 70 Olympic swimming pools every day! This remarkable finding offers scientists a chance to learn about how planets formed around other stars, possibly even older ones than our sun.
The European Space Agency’s Jupiter Icy Moons Explorer (JUICE) made this discovery while heading toward Jupiter and its icy moons. In November 2025, JUICE used its instruments, MAJIS and JANUS, to observe 3I/ATLAS. This comet is only the third object recognized as coming from beyond our solar system.
Like other comets, 3I/ATLAS sprouted activity as it approached the sun. The sun’s heat caused its icy core to change directly from ice to gas—a process known as sublimation. As the gas escapes, it creates a bright coma and tail, features that are typical of comets. What’s interesting is that 3I/ATLAS shone even brighter than expected.
Using MAJIS, scientists identified infrared signs of water vapor and carbon dioxide. These are called “volatiles” because they easily evaporate. Giuseppe Piccioni, part of the research team, mentioned that they estimated the comet is expelling about two tons of material per second. This massive outflow provides an important view into materials that formed around stars long ago.
“The data from MAJIS helps us understand not just this comet but also the conditions that existed when other stars were forming,” Piccioni stated.
Interestingly, the observations were unplanned. JUICE caught wind of 3I/ATLAS only after its discovery on July 1, 2025. Spotting it was tough due to limited time and the faint emissions of the comet. It took months for the data to reach Earth, arriving in February 2026.
Pasquale Palumbo, another team member, said, “The wait was long but rewarding. We saw 3I/ATLAS’s intense activity up close for the first time, including its coma, tail, and distinct features like jets and rays.” The data will let scientists examine the comet’s structure and activity over various timescales.
Studies like these are essential, especially with the growing interest in comets and asteroids. According to recent data from NASA, the number of known near-Earth objects has surged to over 27,000, highlighting the need to understand their behavior and origins. Exploring interstellar comets like 3I/ATLAS may provide clues about our own solar system’s past and the evolution of others.
This mission not only showcases amazing technology but also deepens our understanding of the universe and its mysteries. With JUICE set to explore Jupiter and its moons, the possibilities for discovery are endless.
