太阳系的超级水球，地球上的水量连它的零头都没有3

The Galileo probe explored Jupiter"s moon Europa in the late 1990s, revealing it to be primarily composed of silicate rocks and ice, with a potential ocean up to 1000 km deep, making it a massive water reservoir in the solar system compared to Earth. This discovery sparked excitement for further exploration and discussion about the planet"s possible extraterrestrial oceans.