Sounds like Europa, one of Jupiter’s moons that is roughly the size of our own, has loads of water on it. In fact, one ocean is estimated to be up to 100 miles deep! Of course, being as far from the Sun as it is, Europa is a frosty hunk of ice. At least on the surface. Down below, however, there is liquid water, and where there is water, there could also be life forms.
Turns out that Europa is also extremely acidic, and acidic conditions don’t provide the best conditions for multi-cellular life. If life does exist on Europa, astrobiologists believe they would be acid-loving microbes similar to microbes that have been found in acidic mine drainage on Earth. Often times our knowledge can make us short-sighted, and we begin to think that we know everything. That thought process has humbled many a human over the years. There still is the possibility that Europa is hiding something we’ve never seen or don’t yet understand.
Europa was the first satellite that was determined to have a tenuous atmosphere. In other words, it has oxygen, and oxygen is conducive to life. Despite the high levels of acidity, Europa could be the best place to look for for extraterrestrial life in our solar system. I wonder if we might uncover a secret, hidden civilization of arctic Gungans. Sure would be a nice way to celebrate the life of Ralph McQuarrie.