Potentially Habitable Moons
The moons pictured are among the most discussed and intriguing in the solar system for astrobiologists. They are potentially habitable, not the planets they orbit. During the Galileo lecture on Jupiter, the global subsurface ocean of water on Europa and the inland seas of Ganymede were discovered. On Saturn, thanks to the Cassini spacecraft, we discovered hot underground waters thanks to geysers on Enceladus, and on the giant Titan, we discovered very cold but liquid hydrocarbon lakes beneath its dense atmosphere.
While Enceladus is currently popular thanks to the Cassini spacecraft, I grew up with the mystery of Europa and the fantasy of what might lie in the deep ocean. My favorite, still, is the Europa fabrication.