Before NASA’s Cassini spacecraft plunged into Saturn’s depths, it performed a final 2017 flyby of Titan, Saturn’s largest moon. This remote world is the only place in the solar system other than Earth that hosts large bodies of standing liquid. Titan’s liquid is methane and ethane instead of water. But these lakes and seas make the moon one of the most interesting places in our solar system. And researchers are just starting to learn how these bodies of liquid change with Saturn’s seasons.