Jupiter’s moons Io and Europa reveal secrets of their violent, contrasting births

Two of Jupiter’s most intriguing moons, Io and Europa, have long puzzled scientists with their striking differences. New findings suggest that these differences were established at their formation, not later in their history. Io, the most volcanic body in the solar system, lacks any signs of water ice on its surface. Europa, conversely, harbors a global liquid ocean beneath its frozen crust. The key to these variations lies in how and where each moon formed around Jupiter, with their distinct compositions set during their earliest stages. No recent studies in The Astrophysical Journal have delved into this topic since 2026, with no published research on the formation of Io and Europa from that year. The study of these moons underscores how early conditions can shape a world's future. Io remains arid and volcanic, while Europa's hidden ocean makes it a prime target for further exploration. These findings help explain why two moons orbiting the same planet evolved so differently.