“Recent work by Cassini scientists suggests that Enceladus [the sixth largest moon of Saturn] has a global ocean of liquid water under its surface. This discovery increases scientists’ interest in Enceladus and the quest to understand the role of water in the development of life in the solar system.
This view looks toward the unilluminated side of the rings from about 0.3 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 29, 2015.”
NASA Jet Propulsion Laboratory
Notes on Wonder 