Europe's JUICE mission will explore the Jupiter ocean moons Callisto, Europa and Ganymede. Here's why they're so weird
The icy Jupiter moons Callisto, Europa and Ganymede all likely host hidden global oceans, but that's not the only reason they stand out.
The icy Jupiter moons Callisto, Europa and Ganymede all likely host hidden global oceans, but that's not the only reason they stand out.