Many people listen to the weather report on the radio before they head out the door in the morning so they can be prepared for the day to come.
Cassini's successful mission of exploration to the Saturn system is over, but planetary scientists are left with a cornucopia filled with important new information that Cassini/Huygens sent back to Earth before its mission ended. A collaborative NASA/European Space Agency/Italian Space Agency mission, the robotic spacecraft was made up of two components. The first was the European Space Agency's (ESA's) Huygens Probe, that had been named in honor of the Dutch mathematician and astronomer Christiaan Huygens (1629-1695), who discovered Titan. The Huygens Probe also closely observed Saturn's lovely system of gossamer rings. The second component, the NASA-designed Cassini Orbiter, was named after the Italian-French astronomer Giovanni Dominico Cassini (1625-1712), who discovered four of Saturn's other intriguing, numerous, and icy moons.
Ganymede, and four other moons dwelling in our Sun's family, possess liquid water beneath their frigid crusts of ice. The others are Saturn's moons, Titan and Enceladus, and two other Galilean moons of Jupiter--Europa and Callisto. Planetary scientists think the oceans of Europa and Enceladus are in contact with rock--thus making these two moons high-priority targets for future astrobiology missions.