In 1610, Galileo spotted a small, smooth moon circling Jupiter and wrote it down; four hundred years later, scientists confirmed it likely holds the largest ocean in the solar system, buried under ice and never once touched by sunlight - Space Daily

In January 1610, Galileo Galilei turned a small telescope toward Jupiter and noticed something that should not have been there: tiny points of light close to the planet, changing position from night to night. He did not see an ocean. He did not see ice. He di…